BANGKOK, Oct. 4 (Xinhua) -- Thai Foreign Ministry lodged a letter to Cambodian embassy Saturday afternoon to protest against what Thai authorities alleged Cambodian soldiers' intrusion into Thai territory and acts to open fire at Thai para-military rangers, which led to two injuries on Friday.
Thai Foreign Ministry Permanent Secretary Virasakdi Futrakul on Saturday invited Cambodia's charge d'affairs in Bangkok to lodge a protest letter.
The response came after Cambodia's similar act of lodging a protest letter to the Thai embassy in Phnom Penh earlier Saturday to blame Thai side for the Friday's border clash.
According to the Aide-Memoire issued Saturday by the Thai Foreign Ministry, the Thai side recorded Friday's clash, citing a report by the Second Army Region of the Royal Thai Army, that the Thai para-military rangers from Suranaree Task Force was patrolling along the border about one kilometer to the west of Phra Viharn (Preah Vihear) Temple at around 3:45 p.m. 0845 GMT within Thai soil when they discovered the intrusion of a group of Cambodian soldiers into Thai territory.
Four unarmed Thai rangers asked the Cambodian soldiers to leave, but the latter received instruction from superiors and started firing guns, first into the air then at the Thai rangers, causing the Thai side to return fire.
Two unarmed Thai rangers were found injured after the exchange of gunfire, according to the account.
The letter went on to say "the above-mentioned intrusion of the Cambodian soldiers into Thailand's territory is a serious violation of Thailand's sovereignty and territorial integrity. Furthermore, the shooting by the Cambodian troops against the unarmed Thai para-military rangers is regarded as a brutal and aggressive act and is contrary to the spirit of friendly relations between Cambodia and Thailand. It also constituted a grave violation of the agreement between the two Armed Forces made during the Special Meeting of the Thailand-Cambodia Regional Committee Meeting in Surin Province on 13 August 20-8 that both sides must refrain from digging trenches in the area around Khao Phra Viharn (Preah Vihear Mountain)."
The Thai government thus "strongly protests against the said act of aggression and the violation of Thailand's sovereignty and territorial integrity committed by the Cambodian soldiers," and demanded the Cambodian government to ensure that similar incident does not recur in the future.
Both sides have claimed their soldiers had acted in self-defense and accused the other side of intruding into their territory.
Earlier reports said one Cambodian soldier was wounded during the clash.
Meanwhile. Lt-Gen. Wiboonsak Neeparn, Thailand's Second Army Region commander said on Saturday that senior officers of both Thai and Cambodian armies were expected to meet next week to discuss the clash.
Wiboonsak, who oversees security affairs in northeastern Thailand, told journalists after visiting the two wounded soldiers at an army hospital in the northeastern border province of Ubon Ratchathani that the shooting took place in a disputed area of Kantharalak district bordering Cambodia, and gave assurances that military officers on both sides would deal responsibly with the situation.
But Wiboonsak described the clash as an "accident" as Cambodian troops were rotating personnel at that time and Thai soldiers misjudged that they had encroached the Thai territory and the clash ensued.
He added that Thai troops would not be reinforced in the disputed area.
He said the two Thai wounded rangers were now out of danger and are expected to stay at the hospital for one week.
Cambodian media reported that the Cambodian government was accusing Thai soldiers of being the first to open fire and went onto warn that "armed provocation by Thai soldiers could lead to very grave consequences, including full scale armed hostility".
Thai Prime Minister and Defence Minister Somchai Wongsawat will visit Cambodia on October 13 to negotiate over the border dispute, Gen Wichit Yathip, an aide of Deputy Prime Minister Chavalit Yongchaiyudh, said Saturday.
Thailand and Cambodia have been engaged in diplomatic quarrels and military stand-off tensions along the disputed border around Preah Vihear and at least two other ancient temples after Cambodia applied to UNESCO successfully to list the temple as World Heritage site in July, which resurrected sentiment among Thais who have been reluctant to accept the 1962 International Court of Justice verdict to award the ownership of the 11th-century temple to Cambodia.
Preah Vihear Temple (Kao Phra Viharn) 
Today saw high-level talks between Thai and Cambodian military leaders following a border skirmish yesterday which left two Cambodian soldiers dead, injuries on both sides, and ten Thai troops captured. Several hours of talks have led to an agreement for joint military patrols along the disputed border.

Wednesday's exchange of fire in the disputed border region surrounding Preah Vihear Temple is the latest in a dispute over an area of scrubland which both Cambodia and Thailand claim. While each side claims the other initiated the clash, government officials in both capitals have sought to downplay the seriousness of the incident and stress that a negotiated settlement is the only reasonable solution. The disputed territory is a little under five square kilometres and was, in 1962, awarded to Cambodia by the International Court of Justice. The decision caused resentment in Thailand which continues to this day.

Downplaying the incident, Cambodian Foreign Minister Hor Namhong spoke of the negotiations in positive terms, stressing the skirmish was, "an incident between soldiers and not an invasion by Thailand". Thai Prime Minister, Somchai Wongsawat stressed the need for the dispute over territory to be resolved peacefully.

According to officials, apart from the two Cambodian soldiers who died in the skirmish, an additional two Khmer troops and five Thais were injured. Thailand has denied the claim by Cambodia that ten soldiers were captured in the disputed territory. On the other side of the border, Cambodian officials have said the captives will be returned upon request.
Location of Preah Vihear Temple. 
The dispute over the contested territory flared up in June; UNESCO awarded the Hindu Preah Vihear Temple the status of World Heritage Site as a Cambodian property, bringing the issue back into the spotlight. The 900-year-old temple sits at the centre of a military build-up on both sides of the border and despite an agreed pull-back in August the situation deteriorated when Cambodia asserted that Thai troops had returned to the entrenched positions that now see around 1,000 soldiers from both sides facing each other. The return of Thai military forces saw the Cambodian Prime Minister, Hun Sen threaten to turn the area into a "death zone".

United Nations Secretary General, Ban Ki-moon spoke yesterday on the incident, expressing grave concern over the escalation of the conflict and loss of life. A spokesperson for the Secretary-General said, "He calls on both parties to exercise utmost restraint and urges them to expedite bilateral talks so that their differences can be resolved peacefully". This is not the first time Ban Ki-moon has spoken on the issue; previously calls for restraint have been issued as the military build-up in the area has continued.

The ongoing dispute and yesterday's escalation have seen moves to take civilians out of harm's way. The government in Bangkok urged Thai citizens in Cambodia to leave the country if they were not there on urgent business. Over 400 returned on a Thai Airways flight following the call to evacuate Thai nationals. With a 2003 dispute and unrest having seen Thailand's embassy in Phnom Penh torched, Cambodian authorities deployed riot police around the building yesterday in case the dispute led to violence. In the disputed region, thousands of Cambodians have left due to the build-up of forces on both sides of the border and increased tensions.

The current flare-up along the border is the second incident this month; on October 3 there was a clash where Thailand claims Cambodian forces crossed the border and fired on Thai rangers causing two injuries. That incident saw both sides exchange protest letters. Thailand claimed that rangers patrolling on their side of the border encountered Cambodian troops and demanded they return across the border. The alleged response was apparently orders from superiors for the Cambodians to begin firing. The strongly-worded complaint stated, "the above-mentioned intrusion of the Cambodian soldiers into Thailand's territory is a serious violation of Thailand's sovereignty and territorial integrity. Furthermore, the shooting by the Cambodian troops against the unarmed Thai para-military rangers is regarded as a brutal and aggressive act and is contrary to the spirit of friendly relations between Cambodia and Thailand."