Philippine troops have seized chemical explosives during a raid on a suspected hideout of communist rebels in a province just outside the capital, an army spokesman said Friday, according to DPA. Major Bartolome Bacarro said no guerrilla was around during the raid Thursday in Tanay town in Rizal province, 50 kilometres east of Manila. He said the chemical explosives, which were found in the form of "black powder granules", were still being tested for identification. They were concealed in two boxes each weighing 50 kilograms. Bacarro said troops have been dispatched to conduct pursuit operations against the rebels. The raid occurred as government troops intensified operations against the guerrillas who have launched more attacks against government and civilian targets. The government earlier withdrew immunity from arrest guarantees against 97 rebel negotiators and staff after Netherlands-based guerrillas leaders refused to return to the negotiating table. Communist rebels have been fighting the government since the late 1960s, making the movement one of the longest-running leftist insurgencies in Asia.