DAVAO CITY, Philippines, 11 May 2003 — A bomb exploded yesterday at a crowded market, killing at least 13 people, in the latest deadly terror attack in the Philippines’ troubled south.

Officials said about 26 others were injured in Koronadal City in the main southern island of Mindanao region, where guerrillas of the Moro Islamic Liberation Front (MILF) and other separatist groups are fighting for an Islamic state. The blast site area was crowded because it was market day for traders in Koronadal, capital of South Cotabato province, about 980 kilometers (610 miles) southeast of Manila.

Two female vendors and three passers-by were killed instantly, and eight others died later at two local hospitals, officials said.

Superintendent Danilo Posadas, Koronadal police chief, said an initial investigation indicated the bomb was fashioned from an 81 mm mortar shell. Col. Agustin Dema-ala, commander of the army’s 301st Infantry Brigade, said one of the fatalities was believed to have carried the bomb.

He said a witness saw a man placing a bag on the sidewalk in front of a glass supply store.

“It went off as he turned his back on it,” Dema-ala said, quoting the witness. “I think it was a premature explosion, but it is possible that it was rigged so that the one carrying it does not know when it will explode.”

Fingers were immediately pointed at the MILF, whose fighters attacked the town of Siocon in Mindanao’s Zamboanga Peninsula just a week ago, killing 36 soldiers and civilians. The MILF immediately disowned and denounced the attack. At the same time, Koronadal Mayor Fernando Miguel said the extremist Abu Sayyaf group, which is on the US list of terrorist organizations, claimed responsibility.

“It is not the handiwork of the MILF because we do not attack civilians,” MILF spokesman Eid Kabalu told DXMS radio.

Kabalu said their attack on Siocon, which the separatist group had admitted to be a “blunder,” was aimed at a military camp but civilians were caught in the crossfire.

In another radio interview, Koronadal Mayor Miguel said a man identifying himself as Abu Solaiman of the Abu Sayyaf called him shortly after the 3:30 p.m. (0730 GMT) blast, warning of “more bombings in the days to come.” The man has been calling since last year demanding 4 million pesos ($75,000) monthly to “spare Koronadal City from bomb attacks,” the mayor said, adding that he had refused.