A wounded blast victim speaks on a cell phone at Oktyabrskaya subway station in Minsk, Belarus, April 11, 2011. An explosion tore through a subway station in the Belarusian capital during evening rush hour Monday. (Sergei Grits/AP)

An explosion at a crowded subway station in Minsk, the capital of Belarus, has killed 11 people and injured dozens.

The blast occurred at 5:55 p.m. Monday in the rear car of a train that was just pulling into the Oktyabrskaya station, in the center of Minsk and where the city’s two lines intersect, news agencies reported.

President Alexander Lukashenko, speaking to reporters at the scene of the explosion, said 11 people were killed and about 100 were injured, the Russian Interfax news agency reported.

The cause of the explosion was not immediately clear and is under investigation. Interfax quoted a police source saying authorities think it was a terrorist act, based on the nature of the injuries.

Lukashenko said he has accepted an offer of help in the investigation from Russian President Dmitry Medvedev.

“Men, we were challenged, we need an adequate response, and it must be found,” Lukashenko said at an emergency government meeting Monday night, Interfax reported. According to Interfax, Lukashenko suggested that outside forces were to blame for the explosion, saying, “Who are they? And I ask you to give an answer to this question as soon as possible.”

Ever since a violent police crackdown on protesters in December, the government of Belarus has been imposing increasingly tough measures on its opponents. As many as 50 people face trial and years in prison for participating in the protest, and some of their attorneys have been disbarred and advocacy organizations warned or shut down.

The explosion occurred just as Lukashenko is facing the prospect of bargaining with Moscow for a $2.7 billion loan to help keep his struggling economy afloat. In the past week, his government has been making friendlier gestures toward the West than at any time since December, presumably to strengthen his negotiating position with Russia.

A severe crackdown after the explosion would run the risk of cutting him off from the West — to Russia’s benefit.

As recently as one year ago, Moscow suffered bombings on its subway system, but Belarus does not have a restive ethnic group like the Chechens or other nationalities who live in Russia’s Caucasus. There had been no reported threats against the Minsk subway system.