MANILA : Philippine police now believe last Friday's explosion at a shopping mall was likely to have been caused by an accidental gas leak, but the owners of the Glorietta 2 mall are rejecting such a theory.

The owners of the Glorietta 2 mall are disputing findings by Philippine police that the powerful explosion last Friday was due to an accident.

Police investigators now believe diesel fumes and methane gas that accumulated in the mall basement could have triggered the blast after they were ignited by a spark from a switch.

But mall owners Ayala Land dismiss this possibility.

They say the basement was well ventilated, and there were no reported defects in the diesel tank prior to the explosion.

Jaime Ayala, President, Ayala Land, says: "Clearly we had our maintenance visiting the basement several times a day. There was nothing out of the ordinary at the basement prior to the explosion at that time."

However, Ayala Land says the company is ready for the eventual outcome of the police investigations.

Relatives of the blast victims could file a class action suit against the mall owners if they are found responsible.

Jaime Ayala says: "This is a very sad and tragic event for our country and we are all interested in helping authorities establish the facts and bring the matter to conclusion so that the country can move forward."

But for the survivors of the Glorietta 2 explosion, it will be very hard to go back to their normal lives. Most of them are still experiencing trauma and shock.

Janitor Monie Amamag says he still cannot sleep soundly at night.

He keeps remembering how he was crushed by a section of the mall that he was cleaning: "I find myself waking up in the middle of the night. Even when I close my eyes, it's hard to sleep. When I got trapped I thought I was going to die. I thought I didn't have a chance to survive."

Given a chance, he says he'd prefer to change his workplace.

He says: "I'm scared of going there again but I have to. That's the only way for me to earn money to feed my family."

Caretaker Marilou Gallelein was at the mall with her two wards when the explosion happened.

She says: "I thank God I survived together with my employer and her children. I'm glad that even though we were hurt we are still alive."

More than 100 people were injured and 11 others killed in the blast. - CNA/ch