At least 21 people were injured in overnight arson attacks on buses and trucks hours after a court here upheld the arrest warrant issued against opposition leader Khaleda Zia and called her a "fugitive", renewing tension in the volatile Bangladesh.

As many as 11 people suffered serious burn injuries as suspected opposition activists hurled petrol bombs on a bus at midnight in northeastern Kishorganj area, officials said. Two of the critically injured passengers were fighting for life, doctors said.

Suspected Bangladesh Nationalist Party (BNP) activists last night also torched some 18 vehicles across the country and attacked a government office in northwestern Laxmipur. In two other clandestine arson attacks, two truckers and a passenger were critically wounded in northwestern Chapainawabganj while a similar attack on an autorickshaw in northeastern port city of Chittagong injured three.Four other persons were injured in other attacks.

Paramilitary Border Guard Bangladesh (BGB), meanwhile, seized five petrol bombs from an intercity train. The new wave of violence erupted last night after a brief lull in the unrest that has witnessed loss of some 115 lives since January 6 after a court yesterday upheld its last week's arrest warrant against Zia, refusing to revoke its order as the 69-year-old BNP chief failed to appear to face graft charges.

Zia's counsels, however, said they would seek a High Court intervention later today for restoring the bail of their client after the Third Metropolitan Special Court retained the warrant, calling her a "fugitive" and saying she must surrender first to seek the bail. The court last week issued the arrest warrant after Zia previously skipped trial for 56 times since the hearing began several years ago on two corruption cases involving over US $650,000 which could see her jailed for life.