A number of deaths have been reported after religious-party activists across Bangladesh clashed with police during protests against the war-crimes trial of members of the Jamaat-e-Islami party.
In Dhaka, several hundred opposition religious-party activists attacked police on Friday as officers intercepted one of their processions heading to the site of a protest against the Jamaat.
At least 50 people were detained in the Bangladeshi capital, Nurul Islam, a senior police officer, said.
The activists threw bricks, detonated homemade bombs, set vehicles on fire and beat reporters while the police fired teargas and rubber bullets to disperse them.
Parts of central Dhaka turned into a battlefield as protesters attacked police with bricks and sticks in front of the national mosque after Friday prayers.
The security forces responded with hundreds of rounds of rubber bullets and tear gas shells, according to witnesses.
Police tried to thwart the protest by locking the gates of the city's Baitul Mukarram mosque where thousands of people were performing their weekly prayers, an AFP photographer at the scene said.
The clashes in Dhaka lasted nearly two hours.
Television footage showed activists on the rampage in other parts of Bangladesh.
A Jamaat activist was killed in the southwestern district of Jhenaidah when protesters fought with the police, Khawja Abdul Hannan, chief administrator of the district, said by phone.
One person was killed in clashes in the northeastern district of Sylhet and two others in the northern district of Gaibandha, police said.
Olama Mashayekh Parishad, an Islamist organisation, has called for a nationwide strike on Sunday to protest what they say are police atrocities.
"We have called the general strike to protest the police brutality and the conspiracy against Islam by a section of atheist bloggers," Shah Mohammad Abdullah Ashraf, one of the organisation's leaders, said.
Mohiuddin Khan Alamgir, home minister, said the government had beefed up security across the nation and blamed Jamaat for creating anarchy in a bid to foil the ongoing war crimes trial.
Liberal bloggers and internet activists have been calling on the government to crack down on hardliners who lead Islamist political parties.
Earlier this month, a special tribunal convicted a senior Jamaat leader, Abdul Qader Mollah, of mass killings during the 1970 liberation war and sentenced him to life in prison.
Another eight leaders of the party are on trial on charges of atrocities during the nine-month conflict that led to the dismemberment of Pakistan and the birth of Bangladesh.
Mollah's life sentence was seen by many in the country as lenient, which triggered a mass protest.
In its first verdict last month, the tribunal sentenced a former Jamaat leader, Abul Kamal Azad, to death in absentia for similar offences.
Tens of thousands of people came out on the streets across the country calling for the death penalty for convicted war criminals, including Mollah.
They have since been camping at Shahbagh, in the centre of Dhaka, to press for their demands.
Meeting their demands, Bangladesh's parliament this week amended a law allowing the state to appeal any verdict in war-crimes trials it deemed inadequate and out of step with public opinion.
Jamaat members say the war tribunal verdicts were politically motivated and have sought for the trials be held under the auspices of the UN.