Dhaka: Violence erupted in Bangladesh on Saturday ahead of a nationwide general strike called by the opposition BNP to protest the "disappearance" of a senior leader, claiming the life of a bus driver who was burnt to death.

Protesters set afire at least six buses in different parts of the Bangladeshi capital and its outskirts, ahead of the day-long strike called by the Bangladesh Nationalist Party.

Mohammad Badruddin, 35, of inter-district Eagle Paribahan service died of burn wounds as he was being rushed to a hospital after the bus was set on fire in Khilgaon area.

The driver and the helper were asleep inside the parked bus when it was torched, officer-in-charge of Khilgaon police station, Mohammad Sirajul Islam, told. While the helper managed to come out of the bus, the driver was killed.

BNP is set to enforce a nationwide daylong general strike on Sunday to protest "disappearance" of party leader Ilias Ali.

Police and fire service officials said four more passenger buses and a government owned microbus were torched and the suspects fled the scenes.

BNP fears Ilias is a victim of what it called was "forced disappearance" even as the government ordered a massive manhunt to search the BNP organising secretary who went missing along with his driver Ansar on Tuesday night.

The elite anti-crime Rapid Action Battalion (RAB) and police personnel carried out an "unsuccessful rescue operation" in Gazipur this evening, officials said.

An opposition delegation led by BNP's acting secretary general Mirza Fakhrul Islam Alamgir earlier met home minister Sahara Khatun, demanding intensified steps to search Ali. But party chief and ex-prime minister Khaleda Zia alleged he was picked up by "government's RAB or any intelligence agency".

"None of those who were involved in killings and disappearances will be spared and if necessary the issue will be taken to international courts," Zia told a press briefing late on Friday.

In a sharp reaction, Prime Minister Sheikh Hasina said on Saturday that BNP itself might have been behind the disappearance as her ruling "Awami League does not believe in politics of forced disseverances or murders".

RAB officials earlier denied the allegation that they had picked up Ali and said the anti-crime special police force had launched an investigation on their own into his disappearance.

The High Court on Friday issued a ruling asking the home secretary, and police and security agency chiefs to explain in 10 days why they would not be ordered to produce Ali before the court.

"My husband Ilias Ali along with his driver Ansar went out at about 9.45 pm on Tuesday with a car... until now I have not get any trace of my husband and the driver," Ali's wife Tahsina Rushdir Luna said in a statement.