At least one student was killed as security forces and opposition activists clashed in Bangladeshi capital Dhaka.

Thousands of police used water cannon and shotguns to stop a mass rally demanding Prime Minister Sheikh Hasina cancel next month's elections.

Hundreds of demonstrators - some throwing home-made bombs - fought the police as they tried to gather at the opposition's headquarters for the so-called "March for Democracy" despite a ban on political gatherings.

Violence broke out after a group of activists from the opposition Jamaat-e-Islami party began marching on the streets.

And a 21-year-old student was killed when security officials clashed with the opposition activists.

"We fired shotguns to disperse the protesters who exploded dozens of small bombs," said assistant police commissioner Nur Alam Siddiqui.

Police and security forces conducted nationwide raids, searching trains and buses to arrest opposition supporters before the march and set up checkpoints at entry points to Dhaka.

Bus operators said they had halted services to the capital on government orders while ferries remained moored.

Ms Hasina's rival, former prime minister Khaleda Zia, had been expected to addressed the rally but security officials surrounded her home, parking sand-laden lorries to stop her leaving.

Police also surrounded Ms Zia's Bangladesh Nationalist Party's Dhaka headquarters and used water cannon on dozens of lawyers from the BNP and its main ally Jamaat outside the supreme court.

Security officials refused to allow the lawyers to leave the premises to join the banned rally.

Local media reported that nearly 1,000 people had been detained over the weekend as part of a nationwide crackdown ahead of January 5 elections, which the opposition is boycotting because Ms Hasina refused to resign to allow a non-partisan government to oversee the vote.

Opposition parties said that those detained were being held because they were activists, but police claimed that they had been arrested on specific charges to prevent acts of sabotage.

Troops have also been deployed across the country to help the civil administration conduct the election.