Updated

Philippine officials say they are negotiating with Muslim rebels holding more than 100 civilians hostage on ending the five-day standoff.

At the same time, President Benigno Aquino III has again warned the guerrillas that his government won't hesitate to use force.

Aquino on Friday visited troops and some of the 15,000 displaced people in southern Zamboanga city, where about 200 fighters from a Muslim rebel faction seized several coastal communities and used residents there as human shields. About a dozen people have died so far as troops sealed off the area and exchanged fire with the rebels.

Military spokesman Lt. Col. Ramon Zagala says lines of communication with the rebels are open but that they're still refusing to surrender.

The rebels accuse the government of ignoring a peace agreement.