Police said Pastor Edison Lapuz, 39, a minister of the Northeastern Leyte Conference of the United Church of Christ of the Philippines (UCCP), was attacked during the burial in Barangay Crossing, some 175 kilometers west of this city.
A peasant leader, Alfredo Malinao, was fatally hit by a stray bullet.
"We condemned this cruel attack on Rev. Edison Lapuz and the other political activist," said Nestor Nirza, Bayan Munas regional information officer.
Lapuz, who was also active in the human rights group Karapatan, sustained two bullet wounds in the head and chest from a caliber .45 automatic, while Malinao was hit in the chest.
"Gunning down Lapuz is testimony that we must all act to end these merciless killings now. Nobody is spared, thus we must act to defend ourselves," said Diane Ragub, campaign and advocacy officer of the Samahan han Gudti nga Parauna.
Three weeks ago, Lapuz convened an alliance of cause-oriented groups and concerned individuals to seek justice for slain lawyer Fedelito Dacut, regional chairman of Bayan Muna who was gunned down last March.
Lapuz was the third Eastern Visayas leader of Bayan Muna slain in the past three months. Four other provincial coordinators of the party-list group in Samar survived assassination attempts.
Since last January, 36 activists have been killed nationwide, including another religious leader, Fr. William Tadena, parish priest of the Iglesia Filipina Independiente (Aglipayan Church) in La Paz, Tarlac.
In a statement, Fr. Allan Jose Arcebuche, OFM, national chairman of the Promotion of Church Peoples Response (PCPR), said that prior to his gunslaying, Lapuz had issued "strong statements against the killings and harassment of activists in Eastern Visayas by the military." With Benjie Villa