DHAKA (AFP) - Bangladesh security forces have arrested more than 7,000 opposition activists since the start of deadly protests a fortnight ago, the government said.

Activists have firebombed buses, cars and lorries, killing 29 people, since the opposition called a nationwide transport blockade to protest the detention of their leader Khaleda Zia.

Industries Minister Amir Hossain Amu told reporters after chairing a cabinet meeting on security in Dhaka that 7,015 people had been arrested in the 15 days since the blockade began.

The crisis began when police confined Zia to her office after she threatened to lead a mass rally against her political rival Prime Minister Sheikh Hasina.

She wants Hasina to call fresh polls after last year's controversial general election, which opposition parties boycotted on the grounds it would be rigged.

The boycott meant most members of the 300-seat parliament were returned unopposed, handing Hasina another five years in power.

Zia, who denies her Bangladesh Nationalist Party (BNP) and its Islamist allies were responsible for firebombings, has also demanded the release of opposition officials and leaders detained over the violence.

Hasina has accused Zia of trying to trigger "anarchy" and ordered the security agencies to hunt down the protesters behind the firebombings.

The United States, Britain and the European Union have expressed concern over the unrest.

The EU, the nation's biggest export destination, has urged Hasina's government and the opposition to hold talks to resolve the crisis.