President Halimah Yacob and Prime Minister Lee Hsien Loong yesterday wrote to their Sri Lankan counterparts to express their condolences after Sunday's attacks.

In her letter to Sri Lankan President Maithripala Sirisena, President Halimah said: "Such senseless and indiscriminate acts of violence against innocent civilians in churches and hotels can never be justified.

"On behalf of the people of Singapore, I convey my deepest condolences and sympathies to those who lost their loved ones in this tragedy. Our thoughts are with the government and people of Sri Lanka during this difficult time."

PM Lee, in his letter to Prime Minister Ranil Wickremesinghe, said: "We stand firmly behind Sri Lanka in its effort to preserve its hard-wrought peace and stability. I am confident that under your leadership, Sri Lanka will remain united and find strength to overcome this grief and adversity."

Separately, the Ministry of Foreign Affairs issued an advisory asking Singaporeans to defer all non-essential travel to the island.

The MFA advised Singaporeans already in Sri Lanka to exercise vigilance, monitor the news closely and heed the instructions of the local authorities. "You should avoid public places where there are large gatherings of people," it added.

Singaporeans are strongly encouraged to eRegister with the Ministry of Foreign Affairs at https://eregister.mfa.gov.sg/

Those in need of consular assistance may contact:

Honorary Consulate-General in Colombo, Sri Lanka

• No 73, Sir James Peiris Mawatha

Colombo 02, Sri Lanka

• Tel: +94-11-5577300, +94-11-2304444, +94-11-5577111

• E-mail: nawaloka@slt.lk

Ministry of Foreign Affairs Duty Office (24 hours)

• Tanglin, Singapore 248163

• Tel: +65-6379-8800/8855

• E-mail: mfa_duty_officer@mfa.gov.sg