At least 257 people were killed and hundreds of others wounded as a series of bomb attacks hit churches and luxury hotels in Sri Lanka on April 21.
Police chief Chandana Wickramaratne said in an audio statement that the dead militants included “two bomb experts.”
“We have seized the explosives they had stored for future attacks,” he added.
Wickramaratne — who was appointed by President Maithripala Sirisena as acting police chief last week after his predecessor was suspended over his failure to act on warnings about the attacks — said public life was slowly returning to normal with the lifting of curfews imposed after the bombings.
Public schools were reopened on Monday, but attendance fell to below 10 percent in many places amid fears of further attacks.
“We have strengthened security for all schools,” Wickramaratne stressed, adding, “We are also conducting a program to create awareness about safety and security in all schools.”
Wickramaratne did not specify the number of those detained over the attacks, but police spokesman Ruwan Gunasekera said on Monday that 73 people, including nine women, were being held.
The local group National Thowheeth Jama’ath (NTJ) has been blamed for the Easter Sunday attacks, but the Daesh terrorist group has also claimed the bombings.
Meanwhile, police said religious tensions have eased at the town of Negombo, north of Colombo, which suffered the highest death toll in the April 21 attacks.
The Roman Catholic Church appealed for calm after Christians attacked dozens of Muslim-owned businesses, homes, and vehicles in the town on Sunday night. Two people were reportedly arrested.