In the wake of Sunday's deadly bombings, a national emergency was declared, starting on Monday at midnight, the office of Sri Lankan President Maithripala Sirisena announced.

Sri Lankan police have found 87 bomb detonators at Colombo's main bus station, according to a spokesman.

The statement comes after the Sri Lankan authorities announced that they had decided to reimpose a curfew as the country continues to recover from Easter Sunday's deadly bombings, which killed nearly 300 people across the country, local media reported.

Reports say that a suspicious parcel has been found near a church in Kochchikade, Colombo. Meanwhile, people are reportedly being evacuated from the area.

​Over 1,000 army personnel have been deployed to provide security in Colombo, the commercial capital and Sri Lanka's largest city.

The Coast Guard of India has also been on high alert and has been actively patrolling the waters in the south of the country in connection with the terrorist attacks in Sri Lanka, the NDTV broadcaster reported, adding that a patrol plane is also involved in this operation.

According to local authorities, the coast guard is searching for participants and organisers of the bombings in Colombo, who may try to penetrate Indian territory by sea.

READ MORE: Sri Lanka Accuses Thowheed Jamath Militant Group of Being Behind Deadly Blasts

The country launched a massive security operation and introduced an initial curfew immediately following the series of bombings that hit the South Asian nation on 21 April.

The curfew, which ended at 6:00 a.m. local time (00:30 GMT) on Monday, was reset to start at 8:00 p.m. (14:30 GMT) on Monday and end at 4:00 a.m. on Tuesday (22:30 GMT on Monday), the News 1st portal reported, citing the Department of Government Information.

At least 290 people were killed and hundreds were injured in eight explosions across Sri Lanka on Easter Sunday. The blasts hit several churches and hotels in Colombo and other cities.

Sri Lankan Health Minister Rajitha Senaratne earlier announced that the series of deadly explosions across the country had been organised by a local terrorist group, Thowheed Jamath, emphasising that the attacks had been carried out with the help of a vast international network.