Bangladesh has been hit by renewed violence, with three more people killed on the eve of elections in which the ruling Awami League looks certain to prevail in a walkover as the main opposition party boycotts the poll.

The Bangladesh Nationalist Party (BNP) called a 48-hour strike from Saturday morning, on top of a transportation blockade, and urged voters to stay away from the “farcical” election.

Without the BNP's participation, only 146 of 300 parliamentary constituencies are being contested.

"I call upon countrymen to fully boycott the disgraceful farce in the name of election of 5 January," BNP chief Begum Khaleda Zia, who has been under what she calls virtual house arrest, said in a statement late last night.

The government has denied that she is confined or under house arrest.

The BNP is protesting against Prime Minister Sheikh Hasina's scrapping of the practice of having a caretaker government oversee elections and many of its leaders are in jail or in hiding.

The office of prime minister has been held by Ms Hasina or Ms Khaleda for all but two of the past 22 years.

The European Union, a duty free market for nearly 60% of Bangladesh's garment exports, has refused to send election observers, as have the United States and the Commonwealth, a grouping of 53 mainly former British colonies.

A ruling party leader was shot dead in southwestern Khulna overnight and a party youth activist was killed in clashes with rival BNP supporters in northwestern Lalmonirhat, police said, as renewed violence flared after several days of relative calm.

Two buses were set on fire in the port city of Chittagong and more than a dozen polling stations had been torched by opposition activists since Friday.

At least 10 people were injured when BNP activists hurled bombs at a railway station and set on fire a train compartment in the northern town of Natore, police said.

More than 100 people have died in the run-up to the election, mainly in rural districts.