People light candles during a vigil in memory of the victims of a string of suicide bomb attacks across the island on Easter Sunday, in Colombo, Sri Lanka April 28, 2019.

Sri Lankan Catholics pray on the road in front of St. Anthony's Shrine, where an explosion took place during mass on Easter Sunday, in Colombo, Sri Lanka May 5, 2019.

A Sri Lankan army soldier searches a class room at a school as schools second term will start on 6th of May, two weeks after a string of suicide bomb attacks on Catholic churches and luxury hotels across the island on Easter Sunday, in Colombo, Sri Lanka May 5, 2019.

Sri Lankan police officers are seen during a search operation at a school premises as schools second term will start on 6th of May, two weeks after a string of suicide bomb attacks on Catholic churches and luxury hotels across the island on Easter Sunday, in Colombo, Sri Lanka May 5, 2019.

A student's bag is searched by a parent as he arrives at his school which opened days after a string of suicide bomb attacks across the island on Easter Sunday, in Batticaloa, Sri Lanka, May 6, 2019.

A student is frisked by a parent as he arrives at his school which opened days after a string of suicide bomb attacks across the island on Easter Sunday, in Batticaloa, Sri Lanka, May 6, 2019.

Soldiers arrive for deployment outside St. Sebastian Church, days after a string of suicide bomb attacks across the island on Easter Sunday, in Negombo, Sri Lanka, May 1, 2019.

Sumathi Karunakaran, 52, who was injured during the bombing of Zion Church on Easter Sunday, prays at a community hall in Batticaloa, Sri Lanka, May 5, 2019.

An injured member of Zion Church, which was bombed on Easter Sunday, cries as she prays at a community hall in Batticaloa, Sri Lanka, May 5, 2019.

A Sri Lankan police officer searches a school premises as schools second term will start on 6th of may, two weeks after a string of suicide bomb attacks on Catholic churches and luxury hotels across the island on Easter Sunday, in Colombo, Sri Lanka May 5, 2019. REUTERS/Dinuka Liyanawatte - RC1A11EB4820

Sri Lankan army soldiers search a class room at a school as schools second term will start on 6th of May, two weeks after a string of suicide bomb attacks on Catholic churches and luxury hotels across the island on Easter Sunday, in Colombo, Sri Lanka May 5, 2019.

A member of Zion Church, which was bombed on Easter Sunday, cries as she prays at a community hall in Batticaloa, Sri Lanka, May 5, 2019.

Few students are seen in an otherwise full clasroom at a school which opened days after a string of suicide bomb attacks across the island on Easter Sunday, in Batticaloa, Sri Lanka, May 6, 2019.

A boy holds a candle during a vigil in memory of the victims of a string of suicide bomb attacks across the island on Easter Sunday, at Lake House in Colombo, Sri Lanka April 28, 2019. Image used for illustrative purpose.

Members of Zion Church, which was bombed on Easter Sunday, pray at a community hall in Batticaloa, Sri Lanka, May 5, 2019. Image used for illustrative purpose

Sri Lankan police officers search a school premises as schools second term will start on 6th, two weeks after a string of suicide bomb attacks on Catholic churches and luxury hotels across the island on Easter Sunday, in Colombo, Sri Lanka May 5, 2019.

A Sri Lankan army soldier searches a class room at a school as schools second term will start on 6th of May, two weeks after a string of suicide bomb attacks on Catholic churches and luxury hotels across the island on Easter Sunday, in Colombo, Sri Lanka May 5, 2019.

People look at the site of an overnight gun battle, between troops and suspected Islamist militants, on the east coast of Sri Lanka, in Kalmunai, April 27, 2019.

Members of Zion Church, which was bombed on Easter Sunday, pray at a community hall in Batticaloa, Sri Lanka, May 5, 2019.