Philippine police issued a warning yesterday of plots to bomb public markets in Manila, two days after three coordinated blasts killed 13 people in the capital?s business district and two southern cities.

President Gloria Macapagal Arroyo?s allies in Congress called on her to convene the national security council to consider a state of emergency for the troubled island of Mindanao, where two of Monday?s explosions happened. Such a declaration, which would allow security forces to search and arrest suspects without warrants, must be approved by Congress if it extends longer than 60 days. ?If indeed there is a need to declare a state of emergency, the president has to consult her security advisers,? Arroyo?s spokesman Ignacio Bunye told reporters. Mindanao is the stronghold of the Moro Islamic Liberation Front, a Muslim separatist group due to restart peace talks with the government of the Roman Catholic country in March.

The island is also home to pockets of militants from several other groups, including Abu Sayyaf rebels who claimed the three explosions in crowded public places on Valentine?s Day. Intelligence officials say they are exploring a possible role in Monday?s attacks by Jemaah Islamiah, a shadowy regional network of militants also associated with al Qaeda. ?We?ve picked up intelligence two days ago about plots to bomb several public markets in Metro Manila,? said Avelino Razon, the capital?s police chief.

Last December, a bomb killed 14 people at a market in General Santos on Mindanao. Six people died in that city after a blast on Monday at a shopping mall. Police were also checking reports a 10-year-old boy was used to sneak a bag with explosives past security at a bus terminal in Davao on Monday evening. Witnesses said a man then collected the bag and planted the bomb that killed another boy, aged 12.

Arroyo vowed on Tuesday to ?wipe out? Abu Sayyaf. She made similar war cries a year ago after more than 100 people died when a bomb planted by Abu Sayyaf sank a ferry near Manila Bay.

Nearly 5,000 troops have been in fierce fighting with about 800 Abu Sayyaf rebels and rogue members of the Moro National Liberation Front (MNLF) on the remote southern island of Jolo since Feb. 7, when the militants ambushed an army convoy. The MNLF signed a peace deal in 1996 but some disaffected members formed alliances with Abu Sayyaf.

The army said yesterday it was scaling back its offensive on Jolo after taking over an MNLF mountain camp near the town of Panamao but that operations would continue to hunt hundreds of rebels who dispersed during bombing runs and artillery fire. ?This is a victory for the Filipino people,? the senior commander in the south, Lieutenant-General Alberto Braganza, said after hoisting the Philippine flag at the captured base.

Brigadier-General Agustin Dema-ala, the military commander on Jolo, told reporters 70 to 100 rebels had been killed in nine days of clashes. Nearly 30 soldiers were dead, he said. The rebels claim they attacked the troops in retaliation for the killing of a Muslim family during military operations.

Investigators said two of the bombs that went off on Monday had been remotely detonated, using mobile phones. Fragments of C-4 explosive, dynamite and an 81mm mortar shell were among the materials used, they said.

Forensic experts from the Australian Federal Police examined a bus burned by the blast in Manila, but Philippine police said there were difficulties gathering evidence because firefighters had doused the vehicle with water.

Another team of Australian police was due to arrive yesterday evening to help the investigation in the south and look for any link with previous attacks by Jemaah Islamiah.

Manny Mogato