Seven soldiers were killed in two separate clashes with communist rebels allegedly planning to launch attacks in the southern Philippines, the military said Friday.

Nine soldiers were also wounded in the fighting on Wednesday outside Davao City and in the province of North Cotabato, the military said.

Four of the soldiers were killed in the clash outside Davao City, some 950 kilometres south of Manila, where the guerrillas were allegedly gathering in a remote village ahead of an attack on an undetermined target, said Lieutenant Vergel Lacambra, an army spokesman.

In North Cotabato, three soldiers were killed when they encountered a separate group of rebels, said Major General Eduardo Ano, a battalion commander.

Communist rebels have been fighting the Philippine government since the late 1960s - one of the Asia's longest-running leftist insurgencies.

Peace talks between the Philippine government and the communist rebels were suspended in 2004.

Efforts to resume the negotiations stalled when the communist party's chairman and his wife were arrested in March 2014 on outstanding warrants for various alleged crimes.