Nearly 200 people were wounded as riot police clashed with thousands of opposition party supporters in the capital, Dhaka, and neighbouring towns.
Police used batons and tear gas to fight protesters who were throwing bricks and destroying vehicles.
Protester Golam Rasul Milon died when he was hit by a tear gas shell in Dhaka's Mahakhali district, the opposition Awami League party said.
A police official confirmed Milon's death, but said it was unknown whether he was struck by a shell or died of a heart attack.
In Sonargaon, outside Dhaka, a police officer died from head wounds after he was pelted with bricks by protesters, his colleague said.
The officer was among several hundred police who clashed with about 5,000 demonstrators - many of them throwing stones - in the town 30km east of Dhaka. Similar clashes were reported in a dozen other towns.
The 14-party opposition alliance urged supporters to stop public transport, including trains and river ferries in the delta nation. Protesters squatted on railroads, stopping trains in several districts, the United News of Bangladesh news agency reported. Long-distance buses were also stopped.
The opposition has called for the removal M.A. Aziz, the chief election commissioner, and his two aides, and for reforms ahead of the general election, which is due in January 2007.
Prime Minister Khaleda Zia has
vowed to complete her term
The alliance accuses election officials of being loyal to Prime Minister Khaleda Zia's government and trying to help ensure its victory in the polls.
Aziz and the government have denied the allegations.
The opposition has held a series of strikes and demonstrations in recent months, and another nationwide strike is planned for Tuesday.
Zia has vowed to stay in power until her five-year term expires in October, when she is constitutionally required to hand over power to a neutral caretaker administration that will supervise elections.