MANILA, Philippines--Dozens of militants hurled paint bombs and spray-painted protest messages on the façade of the Shell main building in Makati City before working hours Monday.

Led by the Bagong Alyansang Makabayan (New Patriotic Alliance), some 100 protesters trooped to the Shell building on Valero Street in Salcedo Village and threw plastic bags filled with paint at its walls.

Others sprayed messages "Oust Gloria" and "No to oil price hikes" in bold orange and red paint on the façade of the building.

Outnumbered, some three security guards could only watch from the sidelines, as they frantically called on their radios for reinforcement.

The lightning protest started at 8 a.m. and ended a few minutes later, Bayan public information officer Arnold Padilla said.

He said the group wanted Shell, one of three major oil companies, to feel the public outrage against the continuing price hikes in oil, which he said almost averaged P2 every week.

Padilla said the group converged at street corners a block away from the building, and then rushed toward the building.

"We made it appear that we were going to Petron. But it was just a decoy. The police and the security guards were all fooled," Padilla said.

He said the three major oil companies should expect similar types of protest action in the future.

Asked why they decided to use paint to express their grievances, Padilla said they knew removing the paint would be a troublesome task.

"We want to irritate them," he said.

Later, utility workers were hard at work spraying water on the paint but the effort did not appear to be working. Bemused office workers taking cigarette breaks watched.