Authorities in Bangladesh's capital have arrested six suspected members of a banned Islamist group blamed for recent deadly attacks, including one last month that killed 20 people.

Rapid Action Battalion spokesman Mufti Mahmud Khan said Wednesday that the arrests were made in separate overnight raids in Dhaka. He said the suspects belong to the outlawed group Jumatul Mujahedeen Bangladesh.

The group is blamed for last month's attack on a restaurant in Dhaka that killed 20 people, including 17 foreigners. It also is blamed for a July attack on a major Eid prayer gathering north of Dhaka that left four dead, including two police officers.

Khan said the suspects told authorities during interrogation that they were preparing for another attack in Dhaka.