Leaders and activists of main opposition BNP and its ally Jamaat-e-Islami have clashed with police during a demonstration at its headquarters in the Bangladeshi capital, Dhaka.
Police fired tear gas shells and rubber bullets to break up Wednesday's anti-government protests, injuring scores of people.
The strikes were called after a special tribunal sentenced a top leader of Jamaat-e-Islami to death for alleged atrocities during the country's 1971 independence war.
Since last Thursday, when Delwar Hossain Sayedee was sentenced, at least 61 people have died in clashes, mainly between police and Jamaat-e-Islami activists across the country.
Sarwar Hossain, a protester, said the chaos began when hundreds of protesters attempted to join the rally in front the main opposition party's headquarters.
Hossain said they clashed with police, who fired rubber bullets and tear gas.
"We fled through an alley when the situation turned violent," he said. "Many of us have been injured."
The Daily Star newspaper said several crude bombs were thrown at police.
Another daylong general strike
The Bangladesh Nationalist Party called another daylong general strike on Thursday in response to Wednesday's police action.
Jamaat-e-Islami campaigned against the creation of Bangladesh during a nine-month independence war with Pakistan 42 years ago, but denies any involvement in war crimes. The government says three million people died, 200,000 women were raped and millions were forced to flee to neighboring India during the war.
The government initiated the war crimes trials in 2010. Prosecutors have put 12 people on trial, including 11 opposition politicians belonging to Jamaat-e-Islami and the Bangladesh Nationalist Party.
The parties say the trials are politically motivated and aimed at suppressing the opposition.
Jamaat-e-Islami supporters have attacked police, government offices and homes of minority Hindus, uprooted railroad tracks, and set fire to trains and other vehicles.