The clashes resulted in displacement of thousands on both sides of the border [EPA]

A Thai soldier has been killed in fresh border clashes with Cambodian troops, taking the death toll from recent fighting to 18.

Three other Thai troops were wounded in the skirmishes late on Monday and early Tuesday, Colonel Sukit Subanjui, a Thai army spokesman in the northeast border region, said.

"Both rounds of fighting involved assault rifles and mortars," he said.

Cambodia said one of its soldiers was wounded.

Despite the continued sporadic clashes, the situation had improved enough on Monday for many of the 85,000 civilians who had sought refuge in temporary camps or temples on both sides to return home, authorities said.

"The Thais that evacuated can return home because the gun battle has subsided," Suthep Thaugsuban, the Thai deputy prime minister, told reporters.

But he added: "We have to be fully vigilant."

Eight Thai troops and nine Cambodian soldiers have died since April 22 in the conflict around two disputed temples on the border.

Bangkok has said a Thai civilian was also killed and some homes were damaged on both sides.

The neighbours have come under increasing international pressure to end the violence.

An attempted truce announced on Thursday after military-level negotiations proved short-lived, but the fighting has since become less intense and appears to be confined to a smaller area away from civilian populations.

The relationship between the two countries has been strained since the 900-year-old temple Preah Vihear was granted UN World Heritage status in July 2008.

The World Court ruled in 1962 that the temple belonged to Cambodia, but both countries claim ownership of a 4.6-square-kilometre (1.8-square-mile) surrounding area.

Cambodia on Thursday asked the court to clarify that ruling and also requested provisional measures including the removal of Thai forces from the temple area, according to a document published on the International Court of Justice website.

The most recent deadly clashes have been mainly centred around two temple complexes about 150km west of Preah Vihear.