Shaykh Abdur Rahman, chief of the outlawed Jamaat-ul-Mujahideen (JMB), has surrendered to police in Sylhet in north-eastern Bangladesh.
On Wednesday, police had surrounded a house, reportedly full of explosives.
Early on Thursday, Mr Rahman gave himself with two others, and was taken away for questioning, police said.
The JMB has been blamed for a wave of bombings in the country since August last year, which have killed at least 28 people.
'No surrender'
The operation, involving more than 500 members of the elite Rapid Action Battalion, police and the paramilitary Bangladesh Rifles began late on Tuesday night.
They surrounded the two-storey house and used loudspeakers to urge Shaykh Abdur Rahman to give himself up.
The wife of Mr Rahman and eight others were taken into police custody on Wednesday after they were sent out from inside the house.
Bombings
Earlier this month, Mr Rahman and another top JMB leader, Siddiqul Islam, alias Bangla Bhai, were sentenced in absentia to 40 years in prison for a bomb attack which killed two judges last November.
Last August, some 500 bombs were set off in all but one of Bangladesh's 64 districts in the space of an hour. Three people were killed and about 100 injured.
More than 100 cases have been filed against members of the Jamaat-ul-Mujahideen, which the authorities blame for the bombing campaign.
The militant group has been demanding the introduction of Islamic Sharia law in the country.
(BBC)
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