A Hercules C-130 aircraft will be dispatched to Thailand to bring back the remains of Malaysians killed in a tour bus crash there yesterday, says Prime Minister Datuk Seri Najib Tun Razak.

"I have instructed our C-130 aircraft to be dispatched there to bring home the remains of Malaysians who were killed in an accident in Chiang Mai," he said in his latest official Facebook posting.

At the same time, Najib said Malaysian Embassy officials in Bangkok were at the scene to provide whatever assistance, including to family members of the Malaysian victims.

"I share the grief of the families. If there are family members or acquaintances of the victims in Malaysia who wish to obtain further information, they can contact the Foreign Affairs Ministry Operations Room at 03-88874570," he said.

Earlier, Deputy Prime Minister Datuk Seri Dr Ahmad Zahid Hamidi said Najib had ordered mercy flights to bring back the remains of the victims.

Thirteen Malaysians were killed and nine others injured when the tour bus they were travelling in, collided with a pick-up truck in Chiang Mai, northern Thailand Sunday morning.

The bus was heading to Chiang Mai from Chiang Rai province when it collided with the truck.