Thailand said it was "shocked" at an Israeli air strike that hit a UN post in Lebanon, killing four international observers.

"We are greatly concerned over the escalation in tensions and shocked by what had happened with the UN observers," foreign ministry spokesman Kitti Wasinond told AFP.

"Thailand urges all parties to find a resolution to end the conflict and to bring peace to the Middle East," Kitti said.

Some 35 of the 100 Thais who had been working in Lebanon have been evacuated. The rest have moved to areas within the country believed to be safe.

The four UN observers were killed when Israeli forces bombarded a UN post in the south Lebanon town of Khiam on Tuesday.