At least two people have died in clashes between opposition protesters and supporters of the ruling party in Chittagong in southeastern Bangladesh.
Another person was killed and 15 others injured on Thursday in Khulna when police fired at demonstrators from the conservative Jamaat-e-Islami party.
The party is demanding the release of its president, Delwar Hussen.
Police said they fired live rounds at 500 supporters of Jamaat-e-Islami during protests to demand the release of the head of its student wing.
The violence is the latest to hit Bangladesh prompted by a continuing war crimes tribunal, at which almost the entire Jamaat leadership is on trial for crimes committed during the 1971 war of independence against Pakistan.
Clash with Jamaat
The latest deaths brought the overall toll from clashes triggered by the trials to 101 since January 21 when the court handed down its first verdicts.
"Police opened fire after they came under attack from 500 Jamaat supporters," Ghulam Rouf Khan, Khulna district police chief, told AFP news agency, adding that the protesters fired guns and hurled home-made bombs at police.
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"A Jamaat man, hit with a bullet in the chest, died on the way to a hospital," Kazi Abu Salek, another Khulna police officer, told AFP.
About 20 Jamaat supporters were struck by bullets and five police officers were injured in the clashes, online newspaper bdnews24.com said.
Earlier on Thursday, police arrested the acting editor of a pro-opposition newspaper on various charges.
Mahmudur Rahman was arrested in a raid on the office of the Bengali-language Amar Desh newspaper in Dhaka.
Leaders of the government's ruling party have accused the daily of inciting violence during recent political unrest.