Bomb blast in Philippines city kills six A POWERFUL bomb has exploded at the centre of the southern Philippines city of Cotabato, killing six people and wounding more than two dozen others, police say. The explosive device was placed in a vehicle - either a motorcycle or a van - parked near a hospital and a school during the afternoon rush hour on Monday, city police chief Senior Superintendent Rolen Balquin said. Cotabato photographer Mark Navales, who was on the scene within half an hour of the blast, described seeing a blood-spattered road strewn with charred bodies and smouldering vehicle parts. "I saw three mangled human remains, one of them burnt," he told AFP. "I have never before seen (the effects of) such a powerful blast in Cotabato," he added. The attack came a month after after the United States, Australia and Canada warned their citizens against travelling to Cotabato and two other southern cities over fresh threats of terrorism. Those killed were motorists passing through Sinsuat Street, the main highway in Cotabato that is lined by commercial establishments. At least 26 others were wounded, including police officers in a vehicle that was passing through the area, he said. No group immediately claimed responsibility. Mujiv Hataman, governor of a regional autonomous area whose office is 800 metres away from the blast site, said the explosion rattled his windows and shattered a quiet afternoon just before Muslims were to end their Ramadan fast. The blast was heard kilometres away. It was powerful," he said. The late-afternoon explosion damaged at least four vehicles and triggered a fire that engulfed a nearby mortuary and a tyre repair shop, he added. Cotabato is a mixed Muslim-Catholic city on the main southern island of Mindanao, where Muslim insurgents have waged a decades old rebellion that has claimed 150,000 lives. It was the second bombing to hit Mindanao in 10 days. A powerful blast at a restaurant packed with doctors and pharmaceutical salesmen left eight people dead on the Mindanao city of Cagayan de Oro on July 26. The Cotabato explosion also came just shortly after the Bangsamoro Islamic Freedom Fighters, a breakaway rebel faction, warned of intensified attacks against the government targets.