298 people, including 154 Dutch nationals, were on board a Malaysia Airlines Boeing 777 that crashed in strife-torn eastern Ukraine on Thursday.
The airline says Flight MH 17 was enroute from Amsterdam to Kuala Lumpur, carrying 283 passengers, including three infants of various nationalities, and 15 crew of Malaysian nationality.
It is still unclear whether there were any South Africans on board the doomed aircraft.
Malaysia's prime minister said last night that the flight crew did not make any distress call, adding that its flight route had been declared safe by the global civil aviation body.
Najib Razak, who addressed a middle-of-the-night news conference after speaking with leaders of Ukraine and the Netherlands, and to US President Barack Obama, said no stone would be left unturned in finding out what happened.
He said Ukrainian authorities believe Flight MH 17 was shot down.
A U.S. official said American intelligence authorities believe a surface-to-air missile took down the plane, but it is not clear who fired it.
He said it appears unlikely the Ukrainian government, which has denied responsibility, shot down the plane because it doesn't have the capabilities.
Pro-Russia separatists fighting the government have also denied any responsibility.
Meanwhile, the UN Security Council will hold an emergency meeting on Friday to discuss the air disaster in eastern Ukraine.
UN Secretary-General Ban Ki-moon has called for a "full, transparent and international investigation" in the rebel-held territory.
Britain, which requested the urgent talks at the Security Council, is calling for a UN-led investigation.
