The power came into force at midnight local time on Monday, Sky News reported. A government minister has blamed militant group National Thawheed Jama’ut for the attacks. Sri Lankan police are currently investigating whether previous warnings of the attack were ignored or missed.
International intelligence agencies warned police of an attack on April 4.
The Defence Ministry also wrote to the police chief informing him of the attacks.
No group has claimed responsibility for the attacks.
Harin Fernando, Sri Lanka’s minister for telecommunications wrote on Twitter: “Some intelligence officers were aware of this incidence.
READ MORE: Sri Lanka explosion: Who are the victims of Easter massacre?
“Therefore there was a delay in action. What my father heard was also from an intelligence officer.
“Serious action needs to be taken as to why this warning was ignored.”
The horrific bomb attacks on hotels and churches killed at least 290 people and wounded nearly 500 on Easter Sunday.
On Monday, Sri Lankan police found 87 bomb detonators at the main bus station in the capital, Colombo.
A van exploded near a church when bomb squad officials were trying to defuse it following the attacks.
Investigators said seven suicide bombers took part in the attacks while a government spokesman said an international network was involved.
International anti-terrorism experts said even if a local group had carried out the attacks, it was likely that al Qaeda or Islamic State were involved, given the level of sophistication.
Two of the suicide bombers blew themselves up at the Shangri-La Hotel on Colombo’s seafront, said Ariyananda Welianga, an official at the government’s forensic division.
The others targeted three churches and two other hotels.