PHNOM PENH, Dec 9, 2025 (BSS/AFP) - Cambodia has retaliated in a reignited border conflict with Thailand, the former leader of Cambodia said Tuesday, after Phnom Penh accused Thai forces of shelling positions overnight in fighting that has killed seven civilians and a Thai soldier.

The Thai military fired shells into the border province of Banteay Meanchey after midnight, killing two people travelling on National Road 56, the Cambodian defence ministry said in a Facebook post.

Ministry spokeswoman Maly Socheata later told reporters that seven civilians had been killed and 20 wounded in Thai attacks as of Tuesday morning.

The ministry said in a separate statement that the Thai army had resumed attacks around 5:00 am Tuesday in border regions, including in the area of centuries-old temples, such as the UNESCO world heritage site, the Preah Vihear temple.

Five days of combat in July between the two Southeast Asian nations killed dozens of people and displaced around 300,000 on both sides of the border before a truce took effect.

The two countries have blamed each other for the renewed fighting, which saw Thailand launch air strikes and use tanks against its neighbour on Monday.

Cambodia's influential former leader Hun Sen said Tuesday his country had retaliated against Thailand, after Phnom Penh denied firing back for two days.

"After being patient for more than 24 hours in order to respect the ceasefire and for time to evacuate people to safety, yesterday evening we retaliated with more (responses) last night and this morning," the Senate president and former prime minister said in a Facebook post.

"Now we fight in order to defend ourselves again," he added.

Tens of thousands of people have evacuated from border regions since the fresh fighting began on Sunday, officials have said.

In Thailand's Surin province, Sutida Pusa, 30, who runs a small food shop, told AFP on Monday that her young and elderly relatives were moved to an evacuation centre the day before, while others stayed behind to guard their property.

She has travelled back and forth between the temporary shelter and her house -- located less than 20 kilometres (12 miles) from the border -- to care for family members in both places.

"I wanted to see the situation first, as the sounds of fighting aren't as loud as during the major clash on July 24," she said.

"We never trust the situation."

Cambodian information minister Neth Pheaktra told AFP that at least four civilians were killed by Thai shelling on Monday in two border provinces.

Around 10 other civilians were wounded, he said on Monday.

The Thai army has said one soldier was killed and 18 others were wounded since Sunday.

It said Tuesday that Cambodian artillery shells had fallen on two civilian homes in Sa Kaeo province, with no casualties reported.

- Century-old dispute -

The United States, China and Malaysia, as chair of the regional bloc ASEAN, brokered the cessation of fighting in July.

In October, US President Donald Trump backed a follow-on joint declaration, touting new trade deals with Thailand and Cambodia after they agreed to prolong their ceasefire.

But Thailand suspended the agreement the following month, and the two sides then traded accusations of fresh clashes.

UN Secretary-General Antonio Guterres, the European Union and Malaysia's prime minister on Monday urged both parties to exercise restraint and halt hostilities.

The conflict centres on a century-old disagreement over borders mapped during France's colonial rule in the region, with both sides claiming a smattering of boundary temples.