Bangladesh police arrested 10 more suspected activists of the Islamist group Jamaat-ul-Mujahideen, blamed for recent serial bombings that killed two people and injured about 100 across the country, police said on Saturday.
Police said the suspected militants were picked up in southeastern and western regions of the country and were placed under the joint interrogation of police and army troopers.
"The investigation is progressing satisfactorily," M. Abdul Quayyum, inspector general of police, told local television.
Police were looking for 500 or more Islamists believed to have been involved in the August 17 bombing campaign in which hundreds of nearly simultaneous blasts rocked the country.
But the group's supreme leader Shayek Abdur Rahman is still at large. Rahman and his close associates are rumoured to have fled Bangladesh, though police say they have no proof.
"Of the nearly 150 now in police custody, dozens confessed their involvement in the bombings. They either carried, or planted and detonated locally made bombs fixed with time devices," said a police officer who asked not to be named.
No one claimed responsibility for the blasts but copies of a leaflet found at most bomb sites carried a call by Jamaat-ul-Mujahideen, a group which is banned, for the introduction of Islamic rule in Bangladesh, a Muslim democracy.
Moulana Fariduddin Mashud, a former director of the government-run Islamic Foundation, and Moulana Abdus Sattar, a leader of the radical Ahley Hadis group, were among those being interrogated. They were arrested at Dhaka airport along with four others while trying to fly abroad.
Police suspect that Mashud and Sattar, who run a number of Islamic non-government organisations, funded the serial bombings.