Dhaka: Members of Rapid Action Battalion (RAB) arrested four alleged members of Jama'atul Mujahideen Bangladesh (JMB), including a pilot of Biman Bangladesh Airlines, who had been planning acts of sabotage on an aircraft, on Tuesday.

The arrested pilot is Sabbir Ahmed alias Amam Sabbir, 31, a first officer of the national flag carrier and son of Habibullah Bahar Azad, who was arrested after a drive at a militant den at Mirpur Mazar Road on September 7 last.

Azad is the owner of the six-storey building where the militant hideout was busted.

Three other arrestees are Azad's wife Sultana Parvin, 55, her close relative Asifur Rahman Asif, 25, and Md Alam, 30, a tea stall owner.

Rab Director (Media) Mufti Mahmud Khan said they arrested the four alleged militants in a drive that began around 2am and lasted till 11am in Mirpur area.

Earlier, the elite force recovered the skulls of seven people, including two women and two children, from the Mirpur militant hideout after the anti-militant operation.

Militant Abdullah, his two wives, two children and two associates blew themselves up detonating explosives in the multi-storey building of Azad in the city's Darus Salam area.

Rab also recovered huge improvised explosive devices (IEDs) while searching the suspected hideout of militants.

Briefing reporters at Rab's Karwanbazar media centre in the city on Tuesday, Mufti Mahmud said the elite force arrested an alleged JMB member, Billal Hosan, 23, from Fatullah in Narayanganj on October 26.

He was a close associate of slain militant Abdullah.

Based on the statement given by Billal, a special team of Rab-4 carried out the drive in Mirpur area and arrested the four suspected JMB members.

Arrested pilot Sabbir had a close relation with militant Abdullah.

Besides, Abdullah, Sabbir and Manik alias Farhad alias Sarwar Jahan held a number of secret meetings before and after the Gulshan Holey Artisan Café attack, Mufti Mahmud said.

During the meetings, Mufti said, they had planned to carry out several subversive acts, including carrying out attacks on the residences of top government officials with planes or hijacking a Bangladeshi plane to any of the Middle East countries to keep Bangladeshi citizens hostage.