New People's Army (NPA) gunmen waylaid three traffic policemen on the outskirts of the southern city of Butuan late on Monday, a police report said on Tuesday.
All three officers were shot dead as they approached the neighbourhood.
The NPA has been fighting a 35-year Maoist insurgency. President Gloria Arroyo's government resumed peace talks with the rebel leadership in Norway last month, but the two sides have not signed a ceasefire.
Meawhile, Abu Sayyaf guerrillas killed a man and abducted his wife and son in the village of Buan in the Tawi-tawi island group in the extreme southern Philippines on Sunday, the military said.
The Abu Sayyaf has been waging a kidnapping and bombing campaign in support of an attempt to set up an independent state in the southern Philippines.
The US government deems the Abu Sayyaf a "foreign terrorist organisation" and has helped train Filipino troops going after the insurgent group.