Gotabaya Rajapaksa takes Saudi plane to Singapore

(CNN) Sri Lankan President Gotabaya Rajapaksa has fled Maldives on board a flight for Singapore, a high-ranking security source in Colombo told CNN, as anger grows in his home country over his refusal to formally resign.

He is expected to arrive at Singapore's Changi Airport on Thursday night, the security source said.

Rajapaksa had been waiting to secure a "private jet" from a close family member in Colombo, but that had "not materialized," the source added.

Rajapaksa left the capital of the Maldives, Malé, on board a "Saudi flight," the source said.

CNN believes the source was referring to Saudia flight 788, which left Malé at 11:30 a.m. local time Thursday.

Saudia is the flag carrier of Saudi Arabia. 

CNN has reached out to the Foreign Ministry of Singapore and Saudia but has not heard back.

Rajapaksa had been in Maldives for one day after fleeing Sri Lanka in the early hours of Wednesday -- the same day he had said he would resign.

Rajapaksa had been in Maldives for one day after fleeing Sri Lanka in the early hours of Wednesday -- the same day he had said he would resign.

But by Thursday, no formal resignation letter had been received by the Sri Lankan parliament's speaker, raising questions about the intentions of an apparently self-exiled leader who appointed the prime minister as acting president during his absence from his island nation.

Shortly after Rajapaksa left the country, protesters stormed Acting President Ranil Wickremesinghe's office to demand his removal. Wickremesinghe responded by calling a nationwide curfew overnight.