Bangladesh's opposition accused pro-government supporters Tuesday of trying to kill their leader Khaleda Zia after her car was shot at and stoned by a mob while campaigning in Dhaka's mayoral election.

Although Zia emerged unscathed from Monday evening's attack, which took place as she stopped to tour a shopping district, supporters voiced alarm at the lack of protection from the official security forces.

The captain of a migrant boat that capsized in the Mediterranean's deadliest disaster in decades was arrested Tuesday on suspicion of causing the deaths of an estimated 800 people.

Prosecutors in the Sicilian city of Catania said they believed Tunisian national Mohammed Ali Malek, 27, was responsible for steering mistakes and the reckless overcrowding which led to the horrifying shipwreck off Libya on Sunday.

Two student activists have been shot dead in Bangladesh, police said Monday, as the largest Islamist party tried to enforce a nationwide strike to protest at the execution of a senior leader.

There were also reports of protesters firebombing vehicles around the country as tensions ran high following the execution late Saturday of Mohammad Kamaruzzaman, a leader of the Jamaat-e-Islami party.

Bangladesh authorities on Saturday hanged a top Islamist leader for overseeing a massacre during the nation's 1971 independence war against Pakistan, with hundreds of people in the capital Dhaka celebrating the death of a "war butcher".

Security was tightened outside the jail and across the country as specially trained convicts took Mohammad Kamaruzzaman to a makeshift gallows and hanged him using a rope, in line with Bangladeshi jail procedure.

Bangladesh authorities on Saturday hanged a top Islamist leader for overseeing a massacre during the nation's 1971 independence war against Pakistan, officials said.

"Mohammad Kamaruzzaman has been executed at 10.30pm Bangladesh time (1630 GMT)," law and justice minister Anisul Huq told Agence France Presse. 

At least 25 people were killed and many more injured when a packed bus slammed into a tree in Bangladesh early Thursday, police said.

The driver told a local television station he had lost control of the bus after being attacked by robbers armed with knives who tried to grab the steering wheel.

A court in Bangladesh's north Wednesday sentenced two Indian insurgents to life in prison for using Bangladeshi territory to carry out militant attacks across the border in Assam, a prosecutor said.

Ranjan Chowdhury, alias Major Ranjan, and Prodip Marak were sentenced in a district court in the town of Kishoreganj amid tight security over their roles in a separatist movement in neighboring India's northeast Assam state.

At least 37 people were killed when powerful storms swept Bangladesh at the weekend and left a trail of devastation in the northwest, officials said Monday.

Rescuers and villagers recovered the bodies of victims after the storms flattened thousands of houses, uprooted trees and electricity poles and damaged paddy fields across a large area on Saturday night and Sunday.

Bangladesh's highest court Monday rejected a final appeal by an Islamist leader to overturn his death sentence for atrocities committed during the 1971 independence war, clearing the last legal hurdle to his execution.

The review petition is "dismissed", Chief Justice S.K. Sinha ruled at the Supreme Court, upholding Mohammad Kamaruzzaman's original death sentence.

Bangladesh opposition leader Khaleda Zia left her office for the first time in three months Sunday in a sign of easing tensions after deadly protests plunged the country into a political crisis.

Zia, 69, was taken by car to court where she will seek bail in graft cases against her. Authorities had confined her inside the compound in an upscale district of Dhaka on January 3, after she threatened to lead a massive anti-government rally through the capital on the first anniversary of a disputed national election.