A powerful blast has ripped through a metro station in Minsk, the capital of Belarus, killing at least 11 people and injuring up to 100.

The explosion took place at the Oktyabrskaya station in the centre of the city just before 6pm on Monday as commuters travelled home from work.

Video shot by witnesses on mobile phones showed survivors reeling across a smoke-filled platform where a woman with a damaged leg sat propped against a wall.

In other images, a tide of frightened people rushed out through exit doors into an underpass as men with stretchers descended into the station. At street level, on Minsk's Independence Avenue, emergency workers tended to more than a dozen seriously injured victims in shredded clothes, lying in pools of blood. Some had severed limbs. A young woman wailed "Mum, I'm alive! I'm alive!" into her telephone, while at least two corpses lay under a sheet of plastic.

The Oktyabrskaya station is situated close to the residence of Alexander Lukashenko, the president of Belarus. Lukashenko, a Soviet-style dictator, sent security forces to violently crush an opposition rally after disputed presidential elections in December.

Several opposition candidates were arrested and are awaiting trial on charges of "organising mass public disturbances".

There is likely to be speculation that the blast will play into the hands of the hardline regime, who may use it as an excuse to crack down on the opposition.

News agencies said that President Lukashenko visited the scene and laid flowers.

"I can't exclude that this gift was brought to us from outside, but we need to look at ourselves," he told his defence minister, Yury Zhadobin, at an emergency government meeting."You must check all the warehouses to see if ammunition and explosives are in place."

Lukashenko said the explosion could be connected to an unsolved incident in July 2008 when a bomb exploded in a park in Minsk, injuring about 50 people. "Maybe it's a link in the same chain," he said.

Security sources said it was most likely a terrorist attack, but it was unclear who might have detonated the blast, which happened at rush hour at one of the city's busiest transport hubs. There appeared to be no suicide bomber and Belarus has no history of confrontation with Islamists, like its larger neighbour, Russia.

Witnesses described a scene of horror in the moments after the device went off. "It happened between the second and third carriages of the train on the Moscow line," one man told reporters. "There were a lot of people covered in blood. I carried six young people out of there. I think there are fatalities."

Another man told Interfax: "I heard a muffled sound, like someone opening a champagne bottle, then the wave from the blast blew out the windows in the carriage. There was a great deal of smoke; we even became afraid that we might choke to death." Some witnesses spoke of a crater on the platform, not far from an escalator.