MANILA, April 25 (Reuters) - Philippine soldiers seized over 600 kg (1,320 lb) of a chemical material commonly used in bombs on the southern island of Jolo, where tensions have risen since the beheading of seven labourers by a Muslim rebel group. Lieutenant-Colonel Nathaniel Casem, a battalion commander, told reporters on Wednesday his troops found 25 sacks of ammonium nitrate hidden in a mini-bus near Panamao town, where soldiers had been fighting a rogue group of Muslim rebels since April 14. "These deadly cargo could be used for something big," Casem said. "The amount of explosive material was simply too much for blast fishing or for fertiliser use. We suspect the materials will be used for something more sinister and violent." Casem said the bus driver denied any knowledge of the cargo, which officials suspect was going to be used for attacks in Manila, or areas in the south, including Jolo. There are three main Islamic rebel groups in the Philippines, a mainly Catholic country with a large Muslim minority in the south. Jolo island is a hideout for the country's deadliest Muslim rebel group, the Abu Sayyaf, which last week beheaded seven labourers -- two of them teenagers -- in retaliation for the military killing scores of its fighters and two top leaders. Government troops are also hunting for a rogue commander of the Moro National Liberation Front (MNLF) after he shelled a marines base with mortars earlier this month. The military launched air strikes against Habier Malik and his followers, forcing tens of thousands of villagers to flee their homes. ((Reporting by Manny Mogato, editing by Carmel Crimmins and Sanjeev Miglani; Reuters Messaging: manuel.mogato.reuters.com@reuters.net; +632 841 8913))
