Maj. Jose Broso, spokesman of the militarys Southern Luzon Command, said the New Peoples Army rebels flagged down the jeepney carrying Cpl. Hilario Español and CAFGU member Jimmy Lorio, and told all 20 passengers to disembark.
The rebels ordered Español and Lorio to lie on the ground, and then shot them in the head in front of the other passengers.
They then told the horrified passengers to board the jeepney and head toward Barangay Maslog.
Authorities said the NPA has staged 14 killings and initiated six encounters in Bicol this year.
In Iba, Zambales, suspected NPA guerrillas gunned down a barangay chairman in front of his wife and son Wednesday night.
Mario Payumo, 38, chairman of Barangay Sta. Barbara and president of the towns Association of Barangay Captains, was chatting with his wife, who was carrying their two-year-old son, at about 7:40 p.m. when 15 men in camouflage uniforms appeared.
One of the armed men approached him and asked for his firearm. He was brought inside his house and there, the suspected rebels searched for guns, eventually finding an M-14 grenade launcher, a shotgun, a mobile phone and a portable radio.
Payumo was then dragged about 100 meters from his house and was shot several times. Celso Amo, Bebot Sison Jr.