Nearly 300 people in the Philippines are being held by Muslim rebels.
At least eight people died in clashes between the rebels and government troops Monday, following a rampage through coastal cities in the southern Philippines.
The clashes started after troops blocked Moro National Liberation Front guerrillas brandishing assault rifles from marching into Zamboanga to raise their flag at city hall, military spokesman Lt. Col. Ramon Zagala said.
"We cannot allow another armed force to march around our cities," Zagala said. "That is unacceptable."
Zamboanga is a mostly Christian region.
The Moro group signed a peace deal with the government in 1996. But they now claim the government failed to create an autonomous region for Muslims in the southern Philippines.