Military-grade explosives were used in a bomb in the Philippines capital, Manila, that killed nine people on Friday, police have said.
The blast at the mall blew debris out into the street
A police report said the bomb contained the chemical RDX which is used to make the plastic explosive C4.
No-one has claimed to have carried out the attack on the Glorietta shopping complex in a Manila business district.
Police are examining security camera footage and sifting through rubble for clues as to who carried out the attack.
A ninth body was pulled from the debris at the site of the explosion on Saturday morning.
The powerful bomb was detonated at lunchtime on Friday, shattering windows and sending concrete blocks and other debris through the air.
One-hundred-and-thirteen people were injured.
The country's police chief, Avelino Razon, said terrorists were behind the attack, but he did not know which group.
President Gloria Arroyo said the city's emergency services were on high alert, and 2,000 extra personnel had been drafted in "to prevent a similar occurrence".
"We assure everyone that a full-blown investigation is now under way," she said on local TV.
The president's security adviser Norberto Gonzales said the Islamist militant group Abu Sayyaf has been trying to raise international support over the internet.
"What is more ominous here is they may be planning a bigger attack," he said on Philippines radio.
Militants have targeted the Philippines capital in the past.
In 2004, more than 100 people died when militants 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.