Philippine police have increased security for Independence Day celebrations Monday, following two bombings near the capital. Authorities say one of the blasts wounded eight people.
Police say the injuries occurred when a hand grenade exploded at about five a.m. Sunday in an outdoor market in Lipa - 75-kilometers south of Manila.
Shortly after, a second explosion targeted an old bus that was being used as a temporary police station in Quezon City, a Manila suburb.
No one has claimed responsibility for either blast.
Philippine Police spokesman, Samuel Pagdilao, says the attacks are probably political in nature, designed to scare but not kill.
"This cannot be attributed to terrorist groups," he said. "Those that we have seen carrying out explosions or certain activities that would really terrorize people because they do not care if there would be innocent civilians dead."
Manila is on heightened alert. An extra 7,000 police will join a 6,000 member security detail in the capital on Independence Day.
Police spokesman Pagdilao says security threats could come from opposition leftist groups, right-wing elements in the military, and Communist rebels.
Earlier this year, President Gloria Arroyo declared a one-week national emergency after an alleged plot to topple her government by these forces.
The opposition accuses President Arroyo of fraud in the 2004 elections and unsuccessfully tried to impeach her last year.
But the Philippines also faces terrorist threats from various militant Islamic groups - including Jemaah Islamiyah.