Indonesia says it's determined to find Noordin Mohammed Top, the Malaysian-born extremist it believes was behind Friday's deadly attacks in Jakarta.
It says it's reviewing security procedures in the wake of the suicide bombings at the Marriott and Ritz Carlton hotels.
Noordin Top is also wanted for plotting the Bali bomb attacks in 2002 and 2005.
The Indonesian foreign ministry spokesperson Teuku Faizasyah says the authorities haven't been able to catch Noordin Top in the past because he has a network that assists in disguising him.
But Mr Faizasyah says Indonesian authorities are now determined to find him and unravel his network.
At least nine people, including a New Zealand businessman and two Australians, were killed in Friday's bombings in the Indonesian capital.
Another Australian is missing, feared dead. They were all at the same breakfast meeting.
At least 17 foreigners are among the wounded.
Police are studying DNA and other evidence to try to identify those behind the attacks.
Anti-terror chief Ansyaad Mbai says he believes there are strong indications that Noordin Top was the mastermind behind the blasts.
The BBC reports Top was said to be a key financier for Jemaah Islamiah, but is now thought to have set up his own splinter group.
Police said Friday's bombs contained nails, ball bearings and bolts, identical to ones used by JI.
The attackers paid to stay at the hotel and smuggled in the explosives before detonating them in two restaurants on Friday.
They were in room 1808 in the Marriott. An unexploded bomb and other explosives material were recovered there on Friday.
CCTV footage showed one attacker wearing a cap pulling a bag on wheels into the Marriott restaurant, followed by a flash and smoke.
The Jakarta Marriott hotel was previously bombed on 5 August, 2003: 11 people were killed.
The Australian Embassy in Jakarta was bombed on 8 September, 2004: 11 Indonesians were killed and 180 people were wounded.
Jemaah Islamiah (JI) organised the Bali bombings on 12 October, 2002, in which 202 people were killed, including 88 Australians and three New Zealanders.
Three "Bali bombers" were executed by firing squad in November 2008.
In the second Bali bombings, 23 people were killed in restaurants on 1 October, 2005. The dead included four Australians and three suicide bombers.
Assistance from AFP
Australian Foreign Minister Stephen Smith is now in Jakarta.
He says the Australian Federal Police is providing specialist assistance to the Indonesian authorities.
Mr Smith says Australia is "standing shoulder to shoulder" with Indonesia in the wake of the bombings.