PHANOM RAK: Thailand and Cambodia fought their bloodiest military clashes in more than a decade on Thursday, with 12 people killed as the two sides battled with tanks, artillery and ground forces over a disputed border zone.

The fighting marks a dramatic escalation in a long-running spat between the two neighbours both popular destinations for millions of foreign tourists over an area known as the Emerald Triangle, where the borders of both countries and Laos meet.

The decades-old squabble flared into bloody clashes more than 15 years ago and again in May, when a Cambodian soldier was killed in a firefight.

In Thursday`s clashes, Cambodia fired rockets and artillery shells into Thailand and the Thai military scrambled F-16 jets to carry out air strikes.The Thai public health ministry said one soldier and 11 civilians were killed, most of them in a rocket strike near a petrol station in Sisaket province.

Footage from the scene showed smoke pouring from a convenience store attached to the petrolstation. Provincial officials said most of the dead were students inside the shop when the attack happened.

Thailand said 35 people had been wounded, and accused Cambodia of targeting civilian buildings.

A 30-bed hospital in the town of Phanom Dong Rak in Surin province, just 15 kilometres from the border, was hit by shells which shattered windows and collapsed part of a roof.

The facility, which was also struck in the last major clashes between the two countries in 2011, was partially evacuated onWednesday night as a precaution.

`We got a tip that there would be an attack from Cambodia,` a soldier stationed at the entrance said. `There is no telling when it willbe safe enough for patients to return.

Fighting was focused onsix locations, the Thai army said, with ground troops and tanks battling Cambodian forces for control of territory.

Six Thai air force jets were deployed, hitting two `Cambodian military targets on the ground`, according to Thai militarydeputy spokesperson Ritcha Suksuwanon.

Cambodia has not yet commented on casualties on its side. Defence ministry spokeswoman Maly Socheata refused to answer when asked about the issue at a news conference.-AFP