Bangladesh's main opposition leader was detained for questioning Sunday morning, as clashes continued for a second day between police and protesters against the prime minister ahead of upcoming elections.

Dhaka Metropolitan Police Commissioner Habibur Rahman said the leader of the Bangladesh Nationalist Party (BNP) Mirza Fakhrul Islam Alamgir had been "detained for interrogation".

Rahman told AFP that Alamgir would be questioned over Saturday's violence in which a police officer and a protester were killed, and at least 26 police ambulances were torched or damaged.

Alamgir (75), the BNP's secretary-general, has led the party since BNP chairwoman and two-time former premier Khaleda Zia was arrested and jailed, and her son went into exile in Britain.

The resurgent opposition has been mounting protests to press its demands for months, despite their ailing leader Zia being effectively under house arrest after a conviction on corruption charges.

Saturday's protests were the biggest so far this year, AFP journalists at the site said, and marked a new phase in their campaigning with a general election due before the end of January.