Communist guerrillas killed three Philippine soldiers in the first fatal clash since a newly-elected president offered to restart stalled peace talks, the military said on Sunday.

The soldiers were on the central island of Negros on Saturday investigating reports that New People's Army guerrillas were extorting money from villagers when they clashed with about 10 rebels, leaving three soldiers dead and two wounded, a military report said.

The violence comes just days after President-elect Rodrigo Duterte said he was open to resuming peace talks aimed at ending a decades-old insurgency that has claimed tens of thousands of lives. 

After his May 9 election victory, Duterte's spokesman said the firebrand politician may release jailed communist rebels in an effort to reopen peace talks.

 Philippine vice-presidential candidate senator Ferdinand "BongBong" Marcos is greeted by supporters after attending a mass at a Catholic church in Paranaque city, Metro Manila.

Incumbent leader Benigno Aquino ended talks with the Communist Party of the Philippines in 2013 over the rebels' demand for the unconditional release of their detained comrades, which his government was unwilling to grant.

Duterte, a hardline mayor accused of running vigilante death squads that have allegedly killed more than a thousand crime suspects in the southern city of Davao, is a friend of Netherlands-based Jose Maria Sison, who set up the communist party in 1968.

Duterte, who takes office on June 30, has previously described himself as a socialist.

Running for almost half a century, the communist insurgency has claimed 30,000 lives, according to military estimates.

The rebels' strength has dwindled to less than 4,000 fighters from a peak of more than 26,000 in the late 1980s, according to the military.

However it retains support among the deeply poor in the rural Philippines.