Meanwhile, Britain on Thursday warned against "all but essential travel" to Sri Lanka following the terror attacks on Sunday that claimed at least 359 lives.
"The Foreign and Commonwealth Office (FCO) advise against all but essential travel to Sri Lanka, due to the current evolving security situation following attacks on 21 April 2019," the ministry said on its website.
It added that terrorists "are very likely" to try to carry out further attacks, which "could be indiscriminate, including in places visited by foreigners."
"The extent of any continued threat following the 21 April attacks remains unclear," it said.
Eight British nationals were among those killed in the deadly Easter bombings that targeted tourists and Christian worshippers.
Israel too urged its citizens travelling in Sri Lanka to leave the country, citing an "elevated concrete threat" following deadly Easter bombings there.
Israeli Prime Minister Benjamin Netanyahu has offered aid to Sri Lankan authorities in the wake of the attacks which saw suicide bombers blow themselves up in luxury hotels and churches packed with Easter Sunday worshippers.
The health ministry said medical examiners had completed all autopsies by late Thursday, and had concluded that several victims killed in the series of attacks had been counted more than once.