At least 100 polling stations in Bangladesh have been torched ahead of Sunday's controversial election.

The violence came as the opposition, which is boycotting the vote, began a two-day strike in protest at what it called a "scandalous farce".

At least 100 people have been killed during weeks of election violence.

The opposition wants a neutral caretaker administration to oversee the election, as in previous years - something the government has refused.

Bitter enemies

Police and election officials reported arson attacks at around 100 polling stations in some 20 districts around the country, including in the capital, Dhaka.

Many polling stations are based in schools and other civic buildings.

A government administrator in the south-eastern Chittagong region said there would not be any polls cancelled there as a result of the attacks.

"We've already made a move to shift three polling centres which have been torched by protesters," Mohammad Abdullah told the AFP news agency.

In other violence, police said at least 12 people were injured when a petrol bomb was hurled through the window of a train in the north-west town of Natore.

Security is tight, with some 50,000 troops reportedly deployed around the country for the election period.

The opposition Bangladesh National Party began a nationwide 48-hour strike a day after its leader Khaleda Zia urged supporters to "completely boycott" what she called a "scandalous farce" of an election.

She accused the government of placing her under house arrest - something the authorities deny.

The strike is only the latest in a string of protests by the BNP and its allies - including the Islamist Jamaat-e-Islami party - that has seen a blockade of roads, railways and waterways and the closure of shops, schools and offices.

Scores of opposition supporters have died in police shootings and dozens of commuters have been burnt to death by protesters throwing petrol bombs at strike-defying buses.

One voter in the capital, Dhaka, Hazera Begum, told Associated Press: "I want to go to vote, but I am afraid of violence. If the situation is normal and my neighbours go, I may go."