Saudi Arabia advised its nationals to leave Sri Lanka, Al-Ekhbariya state TV reported on Tuesday, citing the Kingdom's embassy in Colombo.
"Due to the current security situation in the Republic of Sri Lanka, the embassy advises citizens in Sri Lanka to leave," the embassy said in a tweet, the Arab News reported.
The advice follows suicide bomb attacks on hotels and churches that killed more than 250 people, including 42 foreign nationals, on April 21.
The warning follows an announcement by the US ambassador on Tuesday that some of the militants involved in the Easter Sunday bombings on the island were likely still at large and could be planning fresh attacks.
Sri Lankan security forces also said they were maintaining a high level of alert amid intelligence reports that the militants were likely to strike before the start of the holy Islamic month of Ramadan.