The security in the central business district of Metro Manila was tightened after two grenade attacks on the offices of two oil companies there on Friday morning.  

According to a radio report, a group of unidentified men fired a grenade at the Petron Corporation building in Makati at Ayala Avenue around 5:30 AM, shattering its third floor window.

Petron spokesman Virginia Ruivivar said that no casualties were reported in the incident.

"We always have very tight security, especially inside the building but this is an outside attack. They do it by driving by and shooting so it's hard to control that kind of attack," she said in an interview.

Earlier, the Caltex Philippines office on the same avenue was attacked but the grenade fired from a launcher by one of the car-riding suspects did not explode, radio dzMM said.

Caltex spokesman Marian Cathedral said attackers launched a grenade at the Caltex office at 5:15 AM, damaging a window.

As a response to the bombings, the National Capital Region Police Office tightened the security at vital installations in Makati and other high-risk areas in Metro Manila.

Chief Director Avelino Razon Jr. said that additional police would be deployed at business offices of oil companies as well as train stations, malls, and markets.

He also said that they are still trying to determine the group behind the twin attacks.

(Xinhua News Agency November 5, 2004)