DHAKA: Bangladesh police stormed a militant hideout just outside Dhaka Saturday, shooting dead three extremists, including the suspected mastermind of an attack on a cafe that killed 22 mostly foreign hostages last month.

“We can see three dead bodies here,” senior police officer Sanwar Hossain told AFP.

“Tamim Chowdhury is dead. He is the Gulshan attack mastermind and the leader of JMB (Jamayetul Mujahideen Bangladesh),” he said, referring to a Bangladeshi-Canadian citizen believed to be behind the attack on the cafe in Dhaka.

Police earlier staged an hour-long gun battle with extremists at Paikpara in Narayanganj, a city 25 kilometres south of Dhaka, Hossain said.

Bangladesh national police chief A.K.M Shahidul Hoque told AFP police were “99 per cent sure” that Tamim Chowdhury was in the hideout when police launched the assault.

Chowdhury, who returned from Canada in 2013, has been leading the banned JMB, which police say carried out the cafe attack in which 18 foreigners were shot and hacked to death in the country's worst terror attack.

Earlier this month, Bangladeshi security forces said they had arrested four women suspected of being members of a home-grown militant group blamed for the cafe attack. A British national, Hasnat Karim, and Tahmid Khan, a student at the University of Toronto were also arrested on suspicion of involvement in the deadly siege.