Philippine troops on Tuesday seized explosive chemicals that were allegedly to be used by al-Qaida-linked Muslim terrorists in planned bomb attacks in the country's troubled south, the military said. The chemicals, consisting of 125 kilos of ammonium nitrate, were seized aboard a truck that passed by a military checkpoint in the coastal village of Rio Hondo in Zamboanga City, 875 kilometres south of Manila, according to Major Eugene Batara. The truck driver, identified as Jasimin Sahid, was detained for interrogation. The seizure brought to more than 900 kilos the total amount of ammonium nitrate confiscated in Zamboanga City since October. Colonel Antonio Supnet, chief of the anti-terrorism task force in Zamboanga City, said troops had been alerted about attempts to bring in such explosives into the port city as part of attempts by Muslim Abu Sayyaf rebels to launch more bomb attacks. "We received intelligence reports that these kinds of explosive chemicals are being shipped to the city to be used in bomb attacks, which are still being planned as a diversionary tactic by the Abu Sayyaf," he said. The military has been conducting a massive offensive against Abu Sayyaf rebels and two top Jemaah Islamiyah (JI) militants - Dulmatin and Omar Patek - on the nearby island of Jolo since August. In October, a series of deadly bombings in the southern provinces of Maguindanao and North Cotabato were blamed on attempts by the rebels to divert military attention from the Jolo operations. The attacks killed six people and wounded more than 30 others.