BANGKOK - A Thai F-16 fighter jet bombed targets in Cambodia on July 24, both sides said, as weeks of tension over a border dispute escalated into clashes that have killed at least 12 people, including 11 civilians.

Of the six F-16 fighter jets that Thailand has readied to deploy along the disputed border, one of the aircraft fired into Cambodia and destroyed a military target, the Thai army said.

Both countries accused each other of starting the clash early on July 24.

“We have used air power against military targets as planned,” Thai army deputy spokesman Richa Suksuwanon told reporters. Thailand also closed its border with Cambodia.

Cambodia’s Defence Ministry said the jets dropped two bombs on a road, and that it “strongly condemns the reckless and brutal military aggression of the Kingdom of Thailand against the sovereignty and territorial integrity of Cambodia”.

The skirmishes came after Thailand recalled its ambassador to Cambodia late on July 23 and said it would

, after a second Thai soldier in the space of a week

Thailand’s health minister said 11 civilians, including a child, and one soldier were killed in artillery shelling by Cambodian forces while 24 civilians and seven military personnel were wounded. There was no immediate word of casualties in Cambodia.

“The Thai Army condemns Cambodia for using weapons to attack civilians in Thailand. Thailand is ready to protect sovereignty and our people from inhumane action,” the country’s military said in a statement.

Prime Minister Anwar Ibrahim of Malaysia, the current chair of Southeast Asian bloc Asean in which Thailand and Cambodia are also members, urged calm and said he would speak to leaders of both countries to peacefully resolve their dispute.

China also expressed concern at the fighting and said it was willing to play a role in promoting de-escalation.

Thai residents, including children and the elderly, ran to shelters built of concrete and fortified with sandbags and car tyres in the Surin border province.

“How many rounds have been fired? It’s countless,” an unidentified woman told the Thai Public Broadcasting Service while hiding in the shelter, with gunfire and explosions heard intermittently in the background.

Cambodia’s Foreign Ministry said Thailand’s air strikes were “unprovoked”, and called on its neighbour to withdraw its forces and “refrain from any further provocative actions that could escalate the situation”.

For more than a century, Thailand and Cambodia have contested sovereignty at various undemarcated points along their 817km land border, which has led to skirmishes over several years and at least a dozen deaths, including during a week-long exchange of artillery in 2011.

Tensions were reignited in May following the killing of a Cambodian soldier during a brief exchange of gunfire, which escalated into a full-blown diplomatic crisis and has now triggered armed clashes.

Landmines

The clashes began early on July 24 near the disputed Ta Moan Thom temple along the eastern border between Cambodia and Thailand, around 360km from the Thai capital Bangkok.

Thailand’s military said in a statement that nine people have been killed across three border provinces, including an 8-year-old boy in Surin.

“Artillery shell fell on people’s homes,” Mr Sutthirot Charoenthanasak, district chief of Kabcheing in Thailand’s Surin province, told Reuters, adding that district authorities had evacuated 40,000 civilians from 86 villages near the border to safer locations.

“Two people have died,” he added.

Video footage showed a plume of thick black smoke rising from a gas station in the neighbouring Thai Sisaket province, as firefighters rushed to extinguish the blaze.

Six people were killed and 10 wounded at the site, the military said, adding that another person was killed in the border province of Ubon Ratchathani.

“The Thai Army condemns Cambodia for using weapons to attack civilians in Thailand. Thailand is ready to protect sovereignty and our people from inhumane action,” it said in a statement.

The military said Cambodia deployed a surveillance drone before sending troops with heavy weapons to an area near the temple.

Cambodian troops opened fire and two Thai soldiers were wounded, a Thai army spokesperson said, adding that Cambodia had used multiple weapons, including rocket launchers.

A spokesperson for Cambodia’s Defence Ministry, however, said there had been an unprovoked incursion by Thai troops, and Cambodian forces had responded in self-defence.

Thailand’s acting Prime Minister Phumtham Wechayachai said the situation was delicate.

“We have to be careful,” he told reporters. “We will follow international law.”

An attempt by Thai Premier Paetongtarn Shinawatra to resolve the recent tensions via a call with Cambodia’s influential former prime minister Hun Sen, the

, kicked off a political storm in Thailand, leading to her

Mr Hun Sen in a Facebook post said two Cambodian provinces had come under shelling from the Thai military.

Thailand this week accused Cambodia of placing land mines in a disputed area that injured three soldiers.

Phnom Penh denied the claim, and said the soldiers had veered off agreed routes and triggered a mine left behind from decades of war.

Cambodia has many land mines left over from its civil war decades ago, numbering in the millions, according to de-mining groups.