A bomb exploded Saturday at a political rally by Prime Minister Sheik Hasina Wajed's governing party, killing at least 15 people and injuring 100, police and eyewitnesses said.
More than 300 activists of the Awami League party were crammed inside a small auditorium in the party's office in Narayanganj, 10 miles from the capital, Dhaka, when the bomb went off.
A prominent lawmaker, Shamim Osman, who was speaking when the explosion ripped through the hall, suffered hand and leg wounds.
Police detained a man at the scene but did not provide any details. No group claimed responsibility for the attack, and police did not say if there were any suspects. Wajed has blamed previous attacks on Islamic fundamentalists.
Political rivalries in the South Asian nation are intense and often explode in violence ahead of elections. Street fights between rival activists, and bomb attacks, are common during campaigns. General elections are scheduled in October.
The floors and walls of the building were splashed with blood after the attack, Mosharaff Hossain, a university student who was wounded in the blast, said in a telephone interview.
"The explosion rocked the single-story building as if an earthquake has occurred," Hossain said.
Most of the injured were taken to hospitals in Narayanganj. Several others, including Osman, were driven to hospitals in Dhaka.
On Friday, an explosion was averted when police recovered two bombs from an auditorium in the southeastern city of Chittagong, hours before a concert.