Mar 18, 2008, 11:15 GMT
Manila - A hand grenade exploded near the Philippine presidential palace on Tuesday, wounding at least 18 people, including college students and vendors, security officials said.
The blast occurred as police and military forces went on heightened alert as millions of Filipinos trooped to the provinces and other vacation destinations for the Holy Week, when Thursday and Friday are public holidays.
Director Geary Barias, chief of Manila police forces, said a man allegedly lobbed the hand grenade outside La Consolacion College, a school just a few metres away from the Malacanang presidential palace.
Barias said initial investigation showed that the blast was linked to a fraternity squabble and not related to anti-government protests calling for the resignation of President Gloria Macapagal Arroyo.
'This is a war among a group of students,' he said.
The Presidential Security Group (PSG), which guards Arroyo, her family and Malacanang, will conduct a separate investigation to confirm the cause of the explosion.
'We are conducting parallel efforts because it happened near Malacanang,' said Brigadier General Romeo Prestoza, PSG commander. 'But the initial report is that this is a fraternity war.'
The explosion occurred as leftist students and activists protested outside the presidential residence in Baguio City, 210 kilometres north of Manila, where Arroyo and her family were vacationing for the Easter holidays.
Chanting 'Oust Gloria,' some 20 students scuffled with policemen who pushed them away from the gate of the presidential Mansion House in the country's summer capital of Baguio City.
Police arrested six protesters, who had posed as tourists before they started shouting anti-government slogans.
Arroyo and her entourage had just arrived at the Mansion House after attending graduation ceremonies at the Philippine Military Academy, the country's top military school, when the protests started.
Anti-government groups have vowed to continue mass protests against Arroyo to demand her resignation over allegations of corruption and electoral fraud.
Calls for Arroyo to step down intensified in February after a witness testified in a Senate inquiry that her husband and a key ally received multimillion-dollar commissions from a scrapped government contract with a Chinese firm.
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