Thousands of weapons were looted in the deadly violence during the student-led revolution that toppled Hasina and the immediate chaos after she escaped mass protests and fled to India by helicopter.

More than 3,700 weapons were handed in during an amnesty that ended in early September, with the security forces then launching a weapons sweep to collect the guns.

Colonel Intekhab Haider Khan told reporters that a total of 6,000 illegally-held firearms had been collected, along with 200,000 rounds of ammunition.

"Our operation is still ongoing," Khan said.

The interim government that took over after Hasina granted the armed forces judicial power, allowing them to engage in day-to-day enforcement activities like the police.

"There has been no directive from the government regarding the army's withdrawal," Khan said.

The army rejected reports four people had died in military custody since August, insisting troops were "strictly adhering" to rules.

"Should any complaints arise, we will take necessary action," he said.