Police in Bangladesh have detained almost 200 people after a bomb attack in the city of Khulna in which two policemen died.
The arrests came during an all-night search operation following the bomb attack in the country's third largest city on Tuesday night.
Two other policemen were critically injured when a group of unidentified men threw five bombs at a police patrol team.
Police said they are now questioning the detainees to find out whether any of them were involved in the bomb and said formal arrests and charges will be made if any of them are found to be responsible.
It was the second bomb attack on police in Khulna - which is 135km (85 miles) southwest of Dhaka - in less than two weeks.
Another police officer was killed in a similar bomb attack on 1 March. Investigators are trying to find establish a motive for the attacks.
Police have been asked to remain on high alert and security has been increased in the city.
Bangladeshi police have been attacked with bombs before
The police chief of Bangladesh, Modabbir Hossain Chowdhury, went to Khulna to see the situation for himself.
Also on Tuesday, police in Bangladesh arrested five members of a hardline Islamist group who had bombs and explosives.
They believe they may be linked to a series of bomb attacks in the country over the last year.
The five were arrested in the western town of Chapainawabganj.
The police action against the little-known Jamaat ul Mujahideen group is highly significant because it reflects recognition by the government that hardline Islamist groups do operate in the country.