St Petersburg metro explosion

Russian President Vladimir Putin has thanked St Petersburg's drivers for taking people home while metro services are suspended.

He said many motorists and taxi drivers were offering to carry passengers for free. 

Hundreds of thousands of people in the city are travelling by foot, car, tram or bus while the metro system is closed, Mr Putin added.

AFP/GettyCopyright: AFP/Getty

US President Donald Trump kept his thoughts on events in St Petersburg brief during an event at the White House.

Quote Message: Happening all over the world, absolutely a terrible thing."

Happening all over the world, absolutely a terrible thing."

ReutersCopyright: Reuters

We've been bringing you quick updates as new information comes out about the St Petersburg explosion, and have now compiled a round-up of what we know  here .

Pictures of the aftermath can be found here .

The US ambassador to the UN has said her country stands with Russia against "extremist groups", despite authorities keeping an open mind about the cause of the explosion.

Nikki Haley shared a message of support for the people of St Petersburg, after up to 10 were killed on Monday.

Russia's Investigative Committee, a state body which investigates major crimes, earlier said it was treating the explosion as a suspected "terrorist attack" - but was not ruling out other possibilities.

"Despite the fact that a criminal case under article 205 of the Criminal Code (act of terror) has been opened, the investigation intends on verifying all other possible versions of this incident," the committee said in a statement.

It has not pointed to possible perpetrators.

Senator Viktor Ozerov, who heads the Russian defence committee, said that anti-terror measures appeared to have failed on Monday.

"The tragedy in St Petersburg tells us that, somewhere, the anti-terror measures that have been taken... have not worked," Mr Ozerov said.

Speaking at the Russian parliament, he called for an investigation into the security measures in place on the St Petersburg metro system. 

"Now we need to uncover the reasons why our system failed, and work out a series of measures so as not to allow such mistakes to be repeated." 

His statement was broadcast live on the state-run news channel Rossiya 24.

Getty ImagesCopyright: Getty Images

A woman travelling in the carriage next to the blast has described the moment the explosion ripped through the train to local media.

The woman, named only as Polina, told Bumaga ( in Russian ) it was standing room only as the metro moved between Sennaya Ploshchad and Tekhnologichesky Institut.

Quote Message: There was a deafening bang, then a strong smell and smoke. People were pressed against each other. Two women immediately felt unwell and fell unconscious. Everything happened on the move, the train didn't stop."

There was a deafening bang, then a strong smell and smoke. People were pressed against each other. Two women immediately felt unwell and fell unconscious. Everything happened on the move, the train didn't stop."

When the train finally pulled into the station, she said they "saw that the neighbouring carriage was mangled, window glass was broken, there was no light and there was blood".  

Quote Message: People were being moved out of it. Some were being carried out, others supported."

People were being moved out of it. Some were being carried out, others supported."

Quote Message: The Russian authorities are sensibly being cautious before apportioning blame for Monday's metro blast. An earlier quote by the prosecutor-general that it was an act of terror was quickly retracted.

The Russian authorities are sensibly being cautious before apportioning blame for Monday's metro blast. An earlier quote by the prosecutor-general that it was an act of terror was quickly retracted.

Quote Message: The FSB Security Service, the successors to the Soviet-era KGB, have skilled investigators, including forensic explosive experts. They will have been examining the explosive residue for clues, as well as the second device that was found intact. Their suspicions are likely to focus on two possible suspects, none yet confirmed.

The FSB Security Service, the successors to the Soviet-era KGB, have skilled investigators, including forensic explosive experts. They will have been examining the explosive residue for clues, as well as the second device that was found intact. Their suspicions are likely to focus on two possible suspects, none yet confirmed.

Quote Message: One: An ISIS-inspired group enraged by recent Russian airstrikes in Syria. Two: Chechen nationalists (or even a combination of both).

One: An ISIS-inspired group enraged by recent Russian airstrikes in Syria. Two: Chechen nationalists (or even a combination of both).

Quote Message: Both Chechen militants and international jihadists do have a track record of plotting to attack Russia's transport hubs, notably in Moscow. An estimated 7,000 Russians have travelled to Syria to join extremist groups and some have returned."

Both Chechen militants and international jihadists do have a track record of plotting to attack Russia's transport hubs, notably in Moscow. An estimated 7,000 Russians have travelled to Syria to join extremist groups and some have returned."

The metro driver made the right decision not to stop his train before reaching the station, Russia’s Investigative Committee has said.

In a statement released on their website, the federal investigating authority said his actions may have prevented further victims and allowed for the swift evacuation of the injured.

The blast took place in the tunnel between two stations in central St Petersburg.

Oliver Carroll, the managing editor of the Moscow Times newspaper, has been speaking to BBC World News television.

He said that people in St Petersburg are not used to dealing with such attacks.

There have been attacks in Moscow in recent years, but the last major one was in 2010. In fact, Russia's main cities have been "remarkably terror-free" in the last few years, he says.

Mr Carroll says the security services have been "fairly uncompromising" in the troubled North Caucasus region, which is mainly Muslim, as well as taking "bold action" in Syria.

"So there is the grounds for an Islamic kind of terrorism," he said. "At the same time, there will be various conspiracy theories about the state themselves being behind it."

He cautions, however, that he does not want to give "too much weight" to such theories.

What is without doubt is that the government's response "will be uncompromising".

BBCCopyright: BBC

Russian Prime Minister Dmitry Medvedev has written on Facebook:

Quote Message: All those who were injured in the terrorist attack in St Petersburg metro will receive all the medical help they need. All instructions have been issued to the health and emergencies ministries. My most heartfelt commiserations go out to the friends and relatives of the victims of the explosion. This is our common pain.”

All those who were injured in the terrorist attack in St Petersburg metro will receive all the medical help they need. All instructions have been issued to the health and emergencies ministries. My most heartfelt commiserations go out to the friends and relatives of the victims of the explosion. This is our common pain.”

While Mr Medvedev calls it a terrorist attack, some Russian officials have been careful to not label it as such until their investigations are complete.

CCTV images of the man suspected to be responsible for the St Petersburg explosion are circulating on social media.

The images appear to show a bearded man wearing a hat.

Earlier the Interfax news agency reported that CCTV cameras had captured images of the suspect.

The BBC cannot confirm any of these reports, and Russian officials are still investigating the cause of the explosion. 

Russia has a history of attacks on public transport.

In 2013, two bomb blasts in two days in the south-western city of Volgograd left more than 30 people dead and 62 needing hospital treatment.

The suicide bombings struck at the railway station on 29 December and on a bus on 30 December.

Volgograd's public transport system had already been targeted earlier in 2013. In October, a female suicide bomber killed at least six people when she detonated the explosives on a bus.

Three years earlier, at least 38 people died in a double suicide bombing on the Moscow metro .

Before that, in 2009, a bomb exploded  on a high speed train  travelling between Moscow and St Petersburg, killing 27 and injuring another 130.

All attacks were claimed by Islamist groups.

BBCCopyright: BBC

• An explosion has hit a train between two underground stations in St Petersburg
• Officials say the cause of the blast, between Sennaya Ploshchad and Tekhnologichesky Institut stations, is yet to be determined 
• A spokesman for St Petersburg's governor says at least 10 people have been killed and 50 injured. But the Russian National Anti-Terrorist Committee says the death toll is nine, with 20 hurt
• The committee said an explosive device was later found and made safe at another station, Ploshchad Vosstaniya  
• President Vladimir Putin says all causes, including terrorism, are being investigated
• You can read our main story here
• And here is a gallery with pictures of the aftermath

This is reminiscent of the London and Paris attacks – the hashtag #домой (#Domoi) is a big thing now.

On VKontakte, a social media network popular among Russians, and now also Twitter.

It means ‘Home’ – and ordinary people are using it to help others get home.

Here are two examples from VKontakte:

"Around 6pm. We’re able to take three people to the coastal district. We’re going by the toll road. FREE. #Domoi."

"Guys! I have to get home to Muzhestva Ploshchad. Can anyone get me at least some of the way? #Domoi." 

Rick Macy, 52, from Massachusetts, works in St Petersburg and was in a metro car three stops away. He heard the driver and dispatcher talking about the incident and he got off the train.

Quote Message: What a horrific thing. You could tell there was something happening, the dispatcher had a strained voice. When I heard that, I got off the train and came off the metro. It was horrible."

What a horrific thing. You could tell there was something happening, the dispatcher had a strained voice. When I heard that, I got off the train and came off the metro. It was horrible."

Quote Message: Out on the streets, where I can see from our apartment, [there are] lots of people trying to get home. We are right by the Petrogradskaya, close to the station where the bomb went off. I am grateful that we are safe. We are going to stay home tonight."

Out on the streets, where I can see from our apartment, [there are] lots of people trying to get home. We are right by the Petrogradskaya, close to the station where the bomb went off. I am grateful that we are safe. We are going to stay home tonight."