Thailand and Cambodia have accused each other of new attacks as border clashes continue for a third day, leaving at least 33 people dead and more than 168,000 displaced as international pressure mounts to reach a ceasefire.

Fighting on the Thai-Cambodian border extended into a third day and new flashpoints emerged on Saturday as both sides said they had acted in self-defence in the border dispute and called on the other to cease fighting and start negotiations.

The deadliest conflict between the two nations in 14 years, now in its third day, extended to provinces about 200 miles south of where clashes first began.