Three Philippine soldiers were killed in a landmine blast Tuesday when their patrol stumbled onto a communist guerrilla jungle training camp, a military official said. One other soldier was injured in the explosion on the southern island of Mindanao, said Brigadier-General Ricardo Visaya. It was the latest of a series of deadly clashes this year that have left dozens of combatants dead. "They were on patrol and they saw a lot of tents, but pet dogs alerted the NPA (New People's Army guerrillas) to the troops' approach," Visaya, commander of an army division in the area, told reporters by telephone. "Our troops manoeuvred toward the trees as a gunfight began but the area turned out to be mined, and three of them were killed instantly," Visaya added. He said army reinforcements later captured the camp, which the rebels apparently used for combat training, while the guerrillas fled. The fighting came eight days after the NPA killed eight police commandos in the country's north, also by using a landmine. The government has long condemned the rebels for using such explosive devices, saying they violate international agreements. The NPA, which the military believes has about 4,000 fighters, has for decades been waging an armed campaign that has claimed at least 30,000 lives, according to a government estimate. The government said in April that peace talks with the communists had crumbled and a target of ending the insurgency by 2016 was impossible to achieve.