Riot police used tear gas and batons Monday in the Bangladeshi capital to disperse thousands of stone-throwing protesters demanding postponement of this month's elections and electoral reforms, witnesses said.

About 5,000 protesters tried to overrun barbed-wire barricades manned by police, triggering the clashes in central Dhaka that left several people injured, according to an Associated Press reporter at the scene.

The violence broke out on the second day of a crippling three-day transportation blockade imposed by a 19-party alliance that opposes the Jan. 22 election.

At least 100 people, including police, were injured in similar clashes across the capital on Sunday, the first day of protests that cut the city off from rest of the country, Dhaka newspapers reported.

On Sunday, police used batons, tear gas and rubber bullets on stick-wielding, stone-throwing demonstrators.

Schools and businesses remained closed Monday to avoid being caught in the violence.

In an effort to force its demands, the alliance led by former Prime Minister Sheikh Hasina said it plans to keep blocking roads, railways and river routes Tuesday to isolate Dhaka from the rest of the country.

Protesters accuse the interim government in charge of organizing the elections of favoring their opponents, a four-party coalition led by former Prime Minister Khaleda Zia.

The alliance wants the vote delayed until electoral reforms are complete, including the revision of a voter list.

The country's interim leader, President Iajuddin Ahmed, said he could not change the constitutionally mandated election date.

About 12,000 security forces patrolled Dhaka's streets amid fears of a repeat in violence that has marred previous political protests and left at least 34 dead since October.

Under the constitution, an interim government is charged with overseeing elections and has only 90 days to hold them. Ahmed took over as interim leader from Zia on Oct. 29 and his 90-day term expires on Jan. 25.

Bangladesh has a history of political turmoil. Two presidents have been slain in military coups, and Hasina and Zia have traded premierships since the restoration of democracy in 1991.