Cambodian Foreign Minister Hor Namhong told reporters in Phnom Penh that two Cambodian soldiers were killed and two others wounded in the clash that lasted for about two hours.
The Army's Second Area commander, Lt-General Wiboonsak Neeparn, said one Cambodian soldier was killed and five Thais were injured when fighting broke out over a disputed patch of land along the border.
"One Cambodian soldier died and up to four were injured; on our side we have five soldiers wounded," Wiboonsak told Channel 3 television.
Cambodian Brigadier Hom Sam Ol maintained that his men suffered no casualty or injury and added that 10 Thai soldiers had surrendered to Cambodian troops, a claim that was dismissed by Wiboonsak.
Bangkok and Phnom Penh, meanwhile, reached out to the international community, briefing them with their versions of what had taken place on the ground during the two hours of sporadic gunfight between the two sides.
The Foreign Ministries of the two countries summoned each other's ambassadors and lodged formal complaints about the clashes.
Thailand accused Cambodia of firing the first shot while Cambodia made the same claim.
According to Wiboonsak, gunfight broke out around the Phu Ma Khua hill when a Cambodian unit came across a Thai platoon conducting a routine patrol.
The Cambodians instructed their Thai counterparts to retreat from the disputed hill, an order the Thai unit refused to comply with. Fighting broke out immediately afterwards.
The clashes escalated to Sa Trao, an ancient pond about three kilometres away from the Phu Ma Khua hill, he said.
Cambodian Brigadier Bun Thean was quoted by AFP as saying: "Thai troops entered our territory." He accused Thailand of firing the first shot.
According to a Nation photographer on the ground, a Cambodian unit fired three rockets from a position on high ground, hitting a small Thai army outpost near the ancient reservoir, which is claimed by both countries.
Cambodia upped the stakes, resorting to more firepower, launching three 60mm mortar rounds at a Thai military position.
The Suranaree Task Force from Surin Province were seen mobilising their artilleries to the border area but no rounds have been fired.
Thai military officials on the border identified four of the five injured as Lt Thanapol Pongsua and three rangers, Jarouy Wongkham, Thongsa Khamnon and Kittisak Petpakdee. All were sent to an army hospital in Ubon Ratchathani.
The clashes put all the branches of the Thai Armed Forces on high alert, including the Air Force, which placed its jet fighters on stand by.
The clash sent the teetering Thai-Cambodia relations deeper into abyss even as political leaders and diplomats were trying to pick up the pieces following the ultimatum from Cambodian Prime Minister Hun Sen, who vowed to use military force if the Thai troops did not withdraw from the disputed territory.
Prime Minister Somchai Wongsawat insisted that the situation along the border had returned to normal, but said Bangkok would lodge a complaint with Phnom Penh and added that he was confident the crisis would be resolved peacefully.
"We are not the ones who started the violence," Somchai told reporters.
Foreign Minister Sompong Amornwiwat said he was ready to issue the order for all Thais to be evacuated from Cambodia if need be.
Meanwhile Cambodian officials claimed Thailand violated their airspace hours before the border skirmish.
"The Thai injuries were worse, but there were casualties on both sides," the director-general of Cambodia's Preah Vihear authority, which oversees the site, said by telephone.
"The Thai fighter jet came 8.50am and again at 10.07am to disturb our airspace. Cambodian soldiers wanted to fight then, but they were placated for a while.
"I do not know why fighting happened at 2.15 until 3.30 pm because I was not there," the head of Cambodia's Preah Vihear authority, Hang Soth, said by telephone from a meeting in Phnom Penh.
He said there were casualties on both sides, but that the Thai side had borne the brunt of duel M-79, B-40 and AK-47 exchanges.
Cambodian authorities said all civilians had fled the area and it was now regarded by both sides as a conflict zone.
The Wednesday shoot-out at Eagle Terrage is important to the ongoing dispute over the Preah Vihear temple because whoever controls that area controls access to the temple, which is sacred to both sides.
A similar clash at the same site on October 3 left two Thai soldiers and one Cambodian wounded.