The Philippine police announced, on Tuesday, that the mall explosion that killed 11 people and wounded more than 100 is probably an accident, and not cause of a bomb.

The blast in the Glorietta shopping center centre, in the financial district of Makati City, occurred last Friday, could have been caused by gas that was build-up in the mall’s basement, chief of Manila police forces, Geary Barias, reported.

He said that the anti-bomb investigators did not found any clues at the scene, such as an improvised explosive device component or a crater, which would indicate a bomb explosion.

"What I can say is it's very difficult to support the theory of bombing in the absence of the two critical things," he said.

In addition, he reported that the physical effects of the incident, like the upward direction of the blast, fortify the gas explosion theory.

"The petrochemical experts also examined the layout of the fuel tank and their finding is that it did not follow the standard cylindrical structure that would cause an even distribution of the pressure," Barias said. "Their tank is rectangular and that might have contributed to the explosion."

The basement of the mall contained a generator set, empty drums of diesel, a tank of bunker fuel and the septic tank.

This comes as a relief for the government, which was accused by the opposition of having orchestrated the blast in order to divert the public attention from the corruption and bribery scandal that it is into at this moment.