Fighting on the Thai-Cambodian border has extended into a third day and new flashpoints have emerged.
Both sides are saying they have acted in self-defence and are calling on the other to cease fighting and start negotiations.
At least 30 people have been killed and more than 130,000 people displaced in the worst fighting between the South-East Asian neighbours in 13 years.
There were clashes early on Saturday, both sides said, in the neighbouring Thai coastal province of Trat and Cambodia's Pursat Province, a new front more than 100 kilometres from other conflict points along the long-contested border.
The Thai navy said there were clashes in the coastal province of Trat early on Saturday, a new front more than 100 kilometres from other conflict points along the long-contested border.
Earlier, Thailand's government said it agrees in principle to a ceasefire deal with Cambodia and will consider the proposal put forward by Malaysia.
The worst fighting between the rival nations in more than a decade has now killed at least 20 people and left dozens of others wounded.
Some 130,000 people have been forced to find safety because of the fighting, which expanded along the disputed border during the second day of clashes on Friday.
Both countries blame the other for starting the conflict, with Thailand warning the skirmishes could turn into all-out war.
"It must be stated that throughout the day, Cambodian forces have continued their indiscriminate attacks on Thai territory," the Thai foreign ministry said in a post on X.
"Cambodia's actions demonstrate a lack of good faith and continue to place civilians in danger."
Before the post, Cambodia had accused Thailand of agreeing to the ceasefire deal, before backtracking.
Cambodia's Prime Minister Hun Manet said that decision was "regrettable".
On Friday evening, a Thai military border commander declared martial law in eight districts on the frontier with Cambodia, citing "Cambodia's use of force to enter Thai territory".
In Kuala Lumpur, Malaysian Prime Minister Anwar Ibrahim, the chair of the ASEAN regional bloc, said he would continue to push a ceasefire proposal. Cambodia has backed his plan, while Thailand has said it agrees with it in principle.
"There is still some exchange of fire," Mr Anwar said, according to state news agency Bernama.
He said he had asked his foreign minister "to liaise with the respective foreign ministries and, if possible, I will continue engaging with them myself — at least to halt the fighting".
Thailand accused of using cluster munitions
Fighting re-erupted before dawn on Friday, with clashes reported in 12 locations, up from six on Thursday, according to Thailand's military.
It accused Cambodia of using artillery and Russian-made BM-21 rockets to attack areas that included schools and hospitals.
"The deliberate targeting of civilians is a war crime and those responsible must be brought to justice," it said.
Cambodia has no fighter aircraft and significantly less defence hardware and personnel. It has urged the UN Security Council to address what it says is Thailand's "unprovoked military aggression".
It said Thailand's bombardments had caused "significant and visible damage" to the 11th-century Preah Vihear temple, a UNESCO World Heritage Site that both countries have laid claim to for decades.
Thailand's military called the allegation "a clear distortion of facts".
Cambodia's government expressed outrage at what it said was the use of cluster munitions, calling it a clear violation of international law.
Thailand's military said the country was not a party to the Convention on Cluster Munitions, but that it followed the principle of proportionality "to enhance explosive destruction capabilities against military targets only".
Locals flee from both sides of the border
People living near the conflict zones on both sides of the border have been forced to flee.
Nut Sokkheng, 62, said she and her grandson were injured in fighting that broke out about 4km from Ta Moan, one of the disputed temples along the border.
"I have suffered injuries on my left leg and my grandson broke his right leg. Please help him. He is young and still studies," she said.
"I want to see a peaceful country, not war like that."
Nhib Saran, 62, said he was leaving home for an evacuation area after fighting came close to his home in Samrong district, Uddar Meanchey province.
"I want to leave home, go far from the gunshots from Thailand because I am afraid … in this war, there have been big air strikes. I am afraid of staying home, so I take my children out of the firing area," he said.
Thai farmer Jeenjana Phapan fled her village with her three-year-old son after shells landed in the rice field behind their house.
She left her husband behind to care for their cows and protect their home.
"I hope my husband can hide if more shells come," she said.
Conflict a 'dire challenge' for ASEAN bloc
South-East Asia expert at the Centre for Strategic and International Studies think tank Andreyka Natalegawa told the ABC neither country could afford a full-blown war.
He said it was important to quickly get an independent fact-finder, or neutral observer, to get to the bottom of what sparked the latest round of violence "in a bid to bring these events to a more calm state".
There has never been a war between two member states of the Association of South East Asian Nations (ASEAN) bloc, but he said this conflict presented a challenge to the institution.
"There's a real impetus for parties like Malaysia, as well as other ASEAN member states, including Indonesia and Philippines, Singapore, to take a more firm stance and to actively engage with their counterparts on both sides in pursuit of seeking a resolution," Mr Natalegawa said.
"This current crisis and the prospect of current skirmishes emerging into something greater poses a real dire challenge to the institution."
Thailand had not shown interest in third-party mediation, despite saying it would consider Malaysia's peace proposal.
Mr Natalegawa said that was in line with the country's previous desire to achieve a bilateral solution to tension.
He said the ceasefire proposal was an important step by the ASEAN chair, Malaysian Prime Minister Anwar Ibrahim.
"The question will just be whether there's any appetite on both sides to engage in this sort of mediation," he said.
ABC/wires
