Dhaka, Feb 3 (IANS): At least seven people were burnt to death Tuesday when miscreants hurled petrol bombs at a bus in Bangladesh's Comilla district.

Doctors said the toll could escalate as many suffered serious burns injuries, bdnews24 reported. At least 16 people were injured in the attack.

The fire bombing was reported on the Dhaka-Chittagong highway amid the ongoing Bangladesh National Party (BNP) transport blockade and a three day nationwide strike.

The assault was carried out by the supporters of the blockade, officials said.

A fire service official said the bus was heading for Dhaka from Cox's Bazar when it was attacked by agitators, the report said.

None of the dead could be identified immediately, officials added.

More than 50 people have died in violence unleashed by supporters of the BNP-sponsored nationwide indefinite transport blockade.

Former prime minister and BNP chairperson Khaleda Zia, who is pushing for a snap poll, has refused to call off the blockade despite repeated requests.