MANILA: A powerful explosion ripped through a public market south of Manila, hurting eight people, and a separate blast damaged a commuter bus, police said on Sunday. The two grenade attacks came amid tight army and police security as the Philippines celebrates its 108th independence day on Monday. No group has claimed responsibility for the blasts. “The attacks appeared to be unrelated,” Vidal Querol, Manila’s police chief, told reporters. “We still don’t have any suspect.” In the first attack, eight people were wounded when a grenade placed in a bag went off at dawn in a packed public market in Lipa City, 80 kilometres south of Manila. “Based on our initial report, the blast was caused by a fragmentation grenade placed in a bag that was left near the live chicken section of the market,” said a police spokesman.The wounded were taken to two nearby hospitals for treatment of shrapnel wounds, the police added. Communist New People’s Army rebels were known to be active in the province, but a guerrilla spokesman had denied his group’s role in the assassination attempt on the governor.