A deadly explosion in a shopping centre in the Philippine capital, Manila, was more likely to be an accident than a bomb attack, police say.
The explosion caused huge damage to the upmarket complex
They had earlier suggested the blast, which killed 11 people and injured more than 100 on Friday lunchtime, could have been a terrorist attack.
Detectives now say a more likely cause was a gas build-up in the basement of the Glorietta shopping complex.
The blast sent debris flying and caused panic in the city's business district.
President Gloria Arroyo put the city's emergency services on high alert on Friday afternoon, and 2,000 extra personnel were drafted in.
Over the weekend, detectives said they had found traces of the chemical RDX, which is used to make the plastic explosive C4.
But police now say it was more likely to be an accident.
"Our theory is that it was an accidental gas explosion, based on the facts and evidence that we have gathered in the scene," National Police chief Avelino Razon said.
"But we are not totally discarding the possibility that it was a bomb blast," he added.
Militants have targeted the Philippine capital in the past.
In 2004, more than 100 people died when Islamist fighters from Abu Sayyaf - who are battling the military in the south of the country - blew up a passenger ferry in the capital.
And in February 2005, four people died in a bomb attack on a Manila bus.
The Glorietta centre was the focus of a national emergency in 2003 when mutinous troops took over the complex, sparking a day-long siege.