[naviga:h2]At least 10 dead in Russia blast[/naviga:h2]

ST. PETERSBURG, Russia — At least 10 people were killed today in an explosion on the subway in St. Petersburg, Russian news agencies reported.

President Vladimir Putin, who was visiting the city on an unrelated trip today, said investigators were looking into whether the explosion was a terror attack or if there might have been some other cause.

Russia’s National Anti-Terrorist Committee, which said “several” people were killed and injured, said an unidentified explosive device went off on a train that was traveling between two stations.

The agency that runs the subway said several stations in the city were closed and that an evacuation was under way.

Social media users posted photographs and video from a subway station in the city center, showing people lying on the floor and a train with a mangled door nearby.

Putin was expected to hold talks with the Belarusian president later in the day.

[naviga:h2]Poles put blame on Russians for crash[/naviga:h2]

WARSAW, Poland — Polish prosecutors alleged today that a new analysis of evidence from the 2010 plane crash in Russia that killed the Polish president shows that two Russian air traffic controllers and a third Russian official in the control tower deliberately contributed to the disaster.

Russian President Vladimir Putin’s spokesman quickly rejected the Polish claims.

Poland’s National Prosecutor Marek Kuczynski said there is “no doubt” that one of the causes of the crash was the behavior of those in the control tower. He said they were guilty of “deliberately causing a catastrophe.”

Polish investigators said they want to question the three Russians and cannot reveal details about the evidence until that happens.