A man, whom police identified as the commander of Chittagong unit of banned militant outfit Jama'atul Mujahideen Bangladesh (JMB), was killed in a grenade explosion early today, hours after his arrest with firearms and ammunition, according to the law enforcers.

Md Javed, 26, was killed when the grenade went off during a search operation, said Kushum Dewan, deputy commissioner of Detective Branch of Chittagong Metropolitan Police.

Police arrested Javed and four other JMB men and recovered nine grenades, a pistol, 120 bullets, and bomb-making materials during raids in the port city yesterday evening.

Following the information obtained from the arrestees, a team of detectives conducted a drive with Javed in Oxygen area of the city around 4:45am to recover more firearms and ammunition, the police official said.

Javed sustained injuries as a grenade went off during the search operation there, he added.

He was taken to Chittagong Medical College and Hospital with critical condition. Doctors pronounced him dead there, our Chittagong correspondent reports quoting the police official.