Bombs ripped through two luxury hotels in the heart of Indonesia's capital on Friday, killing eight people and wounding dozens in an attack the president said would damage confidence in Southeast Asia's biggest economy.
Suicide bombers struck the JW Marriott hotel and close-by Ritz-Carlton, both popular with visiting international businessmen and protected by some of the tightest security in Jakarta, as guests sat down for breakfast.
While suspicion was likely to fall on the Jemaah Islamiah (JI) militant group, blamed for a previous Marriott attack as well as bombings on the island of Bali in 2002 that killed 202 people, police chief Danuri said it was too early to speculate.
"We are working on it. We are conducting studies at the crime scene, so we cannot rush things," he said.
The group, which wants to create an Islamic state across parts of Southeast Asia, was blamed for a string of attacks until 2005, but many militants have since been arrested.
A visibly upset President Susilo Bambang Yudhoyono, re-elected this month on the back of improved security and a healthier economy, said the bombings were the act of a terrorist group bent on damaging the country.
"I am sure most of us are deeply concerned, feel very sorry and are crying silently, like the way I am feeling," he told a news conference, adding the perpetrators were "laughing and cheering with anger and hatred".
"They do not have a sense of humanity and do not care about the destruction of our country, because this terror act will have a wide impact on our economy, our business climate, our tourism, our image in the world and many others."
Police said the bombers had checked in to the Marriott as paying guests on Wednesday and had assembled the bombs in their room. A third bomb was found and defused in a laptop computer bag on the 18th floor.
"Room 1808 had become their post since the 15th [of July]," National police chief General Bambang Hendarso Danuri told a news conference, adding two suicide bombers had been killed in the blasts.
Indonesia's TVOne showed closed-circuit television footage of a man they said was the Ritz-Carlton's suspected suicide bomber. He was wearing a baseball cap and pulling a wheelie-bag through the lobby.
International condemnation of the bombings was swift.
UN secretary general Ban Ki-moon said he was sure those responsible would be prosecuted and US president Barack Obama, who lived in Jakarta for four years as a child after his mother married an Indonesian, called the attacks "outrageous".
"These attacks make it clear that extremists remain committed to murdering innocent men, women and children of any faith in all countries," the White House said in a statement.
In New York, the target of the September 11th 2001 hijacked plane attacks, authorities said extra security was mounted at major hotels as a precaution.
Reuters