SINGAPORE, March 15 -- Singapore's Prime Minister Lee Hsien loong has written to Chinese Premier Li Keqiang and Malaysian Prime Minister Najib Razak to convey the city-state's concern over the missing Malaysia Airlines flight MH370, the foreign ministry said on Saturday.

In his letter to Premier Li, Lee said that among over 150 Chinese nationals on board the flight MH370, several are reported to have been working or studying in Singapore. He expressed "deep concern for the passengers and their families" on behalf the Singapore government and people.

"Singapore is assisting Malaysia to locate the missing aircraft. We will continue to support the ongoing efforts by Malaysia and other countries, including China, to find the aircraft as soon as possible," he added.

In his letter to Najib Razak, Lee also express Singapore's deep concern for the safety of the crew and passengers, and solidarity with their families.

Singapore has deployed aircraft and ships to join in the search for the missing aircraft. Lee said they "stand ready to provide any further support that will help in this effort."

Singapore deployed one more aircraft on Friday. The Singapore Air Force's Fokker-50 Maritime Patrol Aircraft took off from Changi Airbase West and headed for the Strait of Malacca with six officers on board.

Singapore has previously deployed six types of military units, including helicopters, planes and vessels.