Philippine forces were fighting Muslim rebels on two fronts Thursday as the government recaptured burning sections of a key southern city besieged by guerrillas opposed to peace talks.

Security forces punched into the Santa Catalina district of Zamboanga city, where thousands of people have fled four days of fighting, as the neighborhood went up in flames, military spokesman Lieutenant-Colonel Ramon Zagala said.

Muslim rebels seized scores more hostages and traded gunfire with Philippines troops Tuesday, in the second day of a stand-off after mounting a deadly attack on a southern city, officials said.

Gunshots rang out at dawn on the coastal outskirts of Zamboanga, in the confrontation between the government and Moro National Liberation Front (MNLF) gunmen aimed at derailing peace talks.

Philippines officials on Sunday warned the public against using unlicensed Chinese-made lipsticks and fake copies purporting to be legitimate brands as they may contain high levels of lead.

The Food and Drug Administration (FDA) issued an advisory saying the products were being sold widely on the streets of many urban areas without the agency's approval.

Philippine troops were locked in a standoff with hundreds of Muslim gunmen who killed six people and took at least 20 hostages in the south on Monday in a bid to derail peace talks.

A night-time curfew was imposed in the southern port city of Zamboanga as armored security forces surrounded between 200 and 300 Moro National Liberation Front (MNLF) gunmen holed up in six coastal villages on its outskirts.

A strong 6.0 magnitude earthquake struck off the northern Philippines late Friday, but there were no immediate reports of damage or casualties, officials said.

The quake was recorded at 7:33pm local time (1133 GMT) with an epicenter about 42 kilometers (26 miles) south of Uyugan town in the Batan Islands, the Philippine Institute of Volcanology and Seismology said.

The Philippines has called home its ambassador to China for consultations, the foreign department said Thursday amid fresh tensions in a long-running maritime territorial dispute.

Foreign department spokesman Raul Hernandez announced ambassador Erlinda Basilio's trip after the defense department accused China of laying 75 concrete blocks on the disputed Scarborough Shoal in the South China Sea.

Two soldiers were killed in a firefight with communist guerrillas in the northern Philippines while in a separate clash police backed by helicopters stormed a rebel base near a mountain resort, officials said Saturday.

Up to 30 New People's Army (NPA) gunmen fought a two-day gunbattle with police forces near the resort town of Sagada, said Chief Superintendent Benjamin Magalong, the regional police chief.

Pentagon chief Chuck Hagel said he and President Benigno Aquino discussed expanding the U.S. military's presence in the Philippines on Friday as the Asian ally looks to defend its territorial claims in disputed waters.

The U.S. defense chief went ahead with his overnight visit to Manila despite a tense showdown over Syria, with U.S. forces prepared to launch punitive strikes against the Damascus regime if ordered by President Barack Obama.

The United States and the Philippines have vowed to maintain freedom of navigation in a Southeast Asia increasingly beset by maritime territorial rows, the two military allies said.

The military chiefs of the two countries made the pledge in the United States on Thursday as their governments held talks on expanding the American military presence in the Philippines, a joint statement said.

An estimated 600,000 people in the Philippines remained at temporary shelters or with relatives on Friday after days of heavy rain that killed 20, officials said.

A day after floods ebbed in the capital Manila, stagnant pools of water and high tides in coastal areas prolonged the misery in the central Luzon plains to the north, civil defense official Josefina Timoteo told Agence France Presse.