Police have arrested another 16 people in connection to a series of bombings in Sri Lanka over Easter weekend which claimed at least 359 lives, officials said on Thursday.
Fresh security measures, including a ban on the use of drones, were introduced as police and security forces continued in their efforts to crack down on the network of people involved in the bombings.
The latest arrests brought the number of suspects in detention up to 76.
Vehicles used by the suspects have also been seized in the operations.
Teams from the United States’ Federal Bureau of Investigation and from international police organisation Interpol were in the country assisting local investigators.
The Civil Aviation Authority also banned the use of drones and unmanned aircraft within Sri Lankan airspace until further notice.
Tight security was maintained around hotels, places of worship and government buildings with authorities carrying out random checks on cars and passenger buses.
On Wednesday, Sri Lankan President Maithripala Sirisena directed two top officials to step down amid allegations they failed to share intelligence reports with him about possible suicide attacks which were available to officials earlier in March.
Sirisena claimed that Defence Secretary, Hemasiri Fernando and Inspector-General of Police, Pujith Jayasundara also failed to inform Prime Minister, Ranil Wickremesinghe and his cabinet.
The country has been under a state of emergency since late on Monday.