Sources now say that only one explosion occurred between two stations at a St. Petersburg, Russia, underground train station. Ten people have died:

“There was one blast in one site in between (stations) as the train arrived at the Technology Institute station from Sennaya (Ploshchad) station,” the source told Reuters.

President Vladimir Putin was scheduled to meet with Belarusian President Alexander Lukashenko in the city today.

*UPDATE 12:16PM

Officials have opened a terrorist investigation:

The Russian Investigative Committee has said on its website that it has opened a criminal case under the Terrorist Act after the St Petersburg bomb.

Earlier, a Russian official used the phrase “terrorist attack” in an interview before the comment was retracted.

The Russian Investigative Committee said it will “continue to check all possible versions of what happened”.

*UPDATE 11:44AM

Officials have revised the death toll back to ten. Seven died at the station, one in an ambulance, and two at the hospital.

They have also released this screenshot from CCTV cameras of the possible suspect:

*UPDATE 10:43AM

I’m seeing tweets that state CCTV cameras picked up images of the suspect. I haven’t seen the pictures yet.

*UPDATE 10:26AM

Casualties lowered to nine people and 20+ injured:

*UPDATE 9:50AM

The Russian prosecutor general has officially called it a terrorist attack.

*UPDATE 9:40AM

Witnesses have started to speak to the media about the explosion:

“We were riding in the neighboring car, and at that time it was very crowded: all the seats were taken and many were standing.

“The explosion went off between stations. There was a thundering clap, followed by a strong smell smell and smoke.

“We all moved to the opposite end of the wagon, people jammed together and two women passed out. This all was happening while the train was still moving, it didn’t stop.

“Everyone got out at Tenologicheskom Institute station. There, we saw that the neighboring wagon was shattered, the windows blown out, no light, blood.”

*UPDATE 9:15AM

The Moscow Times has reported that officials discovered a third unexploded device at the Ploshchad Vosstaniya station.

*UPDATE 9:07AM

From The Telegraph:

Russia’s President Putin has said investigators are looking into what he described as a “possible terror attack”, which is “among the theories” for the St. Petersburg subway blast.

From The London Times:

Police confirmed to the Tass news agency that there had been a blast at Sennaya Ploshchad station in the centre of the city. There were also reports of a second explosion at Tekhnologichesky Institut station.

A video circulated on social media showed passengers standing on a crowded platform shrouded in smoke. At least eight fire engines arrived at the Sennaya Ploshchad station, witnesses said.

*I will update this post as more information comes out.

[Featured image via Twitter]