Prime Minister Lee Hsien Loong has written to Indonesian President Joko Widodo to convey his condolence over the plane crash in Papua, Indonesia.
In the letter, Mr Lee wrote: "I was saddened to hear of the tragic crash of Flight IL 267 carrying 54 people on board in Papua on 16 August 2015.
"On behalf of the Government of the Republic of Singapore, I extend our deepest condolences and sympathies to the families who lost their loved ones in this accident."
The aircraft, a short-haul ATR 42-300 airliner belonging to Trigana Air Service, was carrying 44 adult passengers, five crew and five children and infants when it crashed in Indonesia's remote and mountainous region of Papua on Sunday.
The plane was flying between Jayapura's Sentani Airport and Oksibil, due south of Jayapura, the capital of Papua province, according to Reuters.