The Philippine military is exchanging gunfire for a third straight day with a Muslim rebel group that has laid siege to parts of a main southern city.
Military officials say at least nine people have been killed so far in the standoff with Moro National Liberation Front fighters in Zamboanga City, located on the island of Mindanao.
Troops have surrounded at least four coastal villages where about 200 rebels are said to be holding scores of civilians as human shields. Thousands have fled their homes, leaving large parts of the city of nearly one million people largely deserted and resembling a war zone.
In a statement online, Zamboanga Mayor Maria Isabelle Climaco said negotiations with the rebels are ongoing. She said the fighters have released at least seven of the hostages in exchange for food, but that around 100 civilians are still in the rebels' control.
The MNLF is seeking greater autonomy for the mainly Muslim south. It signed a peace deal with the government in 1996. But some of its members continued fighting, claiming Manila went back on its promises to develop the region.
The group has also protested Manila's peace talks with a breakaway faction, the Moro Islamic Liberation Front. Some members of the MNLF fear that a government peace deal with its rival group could diminish its own influence.
President Benigno Aquino has sent representatives to negotiate with the MNLF rebels, who say they want international mediation to the conflict. A similar situation in 2001 eventually ended with the rebels being allowed to go free after releasing the hostages.
The southern Philippines has been mired in a four decade-long insurgency that has killed more than 150,000 people.
Government troopers arrive to reinforce their comrades after an army officer was killed in the ongoing operation against Muslim rebels, Zamboanga, Philippines, Sept. 19, 2013.
Evacuees line up to receive food as fighting between government forces and Muslim rebels continued, Zamboanga, Philippines, Sept. 19, 2013.
Residents line up for a shower in a stadium turned into an evacuation center in Zamboanga, Philippines, Sept. 18, 2013.
Villagers who fled the fighting between government forces and Muslim rebels rest in their tents along a boulevard in Zamboanga, Philippines, Sept. 18, 2013.
Boats of villagers fleeing the fighting between government forces and Muslim rebels crowd a port in Zamboanga, Philippines, Sept. 18, 2013.
Government troops fire mortars during renewed fighting between government forces and Muslim rebels, who have taken scores of hostages, in Zamboanga city in the southern Philippines, Sept. 16, 2013.
Government troops prepare an assault on Muslim rebels in Zamboanga, Philippines, Sept. 13, 2013.
Government soldiers wearing ammunition prepare to attack Muslim rebels in Zamboanga, Philippines, Sept. 13, 2013.
Government troopers prepare for an assault on Muslim rebels in Zamboanga, Philippines, Sept. 13, 2013.
Firemen rush to put out a fire that razed several homes as government troopers continue their assault on Muslim rebels in Zamboanga, Philippines, Sept. 12, 2013.
A man throws water into a burning house in Zamboanga, Philippines, Sept. 12, 2013.
Residents believed to be hostages wave white cloths as they shout at troops to stop their operation in the continuing standoff with Muslim rebels, Zamboanga, Philippines, Sept.11, 2013.
Residents who abandoned their homes carry their belongings during a standoff in Zamboanga, Philippines, Sept. 10, 2013.