An eyewitness saw smoke rising from the Oktyabrskaya metro station in the city centre [Reuters]

Several people have been killed and scores injured in a blast at a metro station in Minsk near the office of Alexander Lukashenko, the Belarus president.

The country's health ministry said 12 people had died and more than 126 had been injured in the explosion.

Andrei Shved, the country's deputy prosecutor, was quoted as saying that the blast was "an act of terror" by the RIA Novosti news agency.

"Today, at around 17:54, an act of terror struck the Oktyabrskaya station," said Shved, who has been put in charge of the former Soviet republic's investigative team into the blast.

An Associated Press reporter said he saw several inert people being carried out of the station, some with heavy injuries, including at least one with missing legs.

An eyewitness saw smoke rising from the Oktyabrskaya metro station in the city centre and apparent casualties being taken to the surface on stretchers.

One witness, Alexei Kiklevich, said at least part of the station's ceiling collapsed after Monday's explosion.

Igor Tumash, 52, said he was getting off a train when "there was a large flash, an explosion and heavy smoke. I fell on my knees and crawled ... bodies were piled on each other''.

He said he saw a man with a severed leg and rushed to help him. "But then I saw he was dead,'' Tumash said.

An AFP correspondent said the explosion paralysed underground traffic across the city of 1.8 million, resulting in traffic jams and grinding travel in the city centre to a halt.

Lukashenko visited the site of the blast and called an emergency meeting of key ministers for later in the day.

Political tension has been high in Belarus since an election on December 19 gave Lukashenko a fourth term in power, to the dismay of the opposition and the West which denounced the vote as fraudulent.

A police crackdown on an opposition rally against the December vote has led to sanctions by the West, including a travel ban on Lukashenko and his closest associates.

In July 2008, a bomb blast at a concert attended by Lukashenko injured about 50 people in Minsk. No arrests in the case were reported.

Source: Agencies