JAKARTA - Indonesia, reeling after a devastating car bomb attack on a luxury hotel killed up to 16 people, said it would unveil tough new security measures as police on Wednesday hunted for the perpetrators.

Singapore's Straits Times newspaper reported that the Jemaah Islamiah (JI) militant Muslim group had claimed responsibility for the blast, the second major terror attack to hit the world's most populous Muslim nation in a year. The attack badly damaged the JW Marriott Hotel, part of a US chain.

The daily, which did not make clear how it had received the message, said "a JI operative" had described the attack as a "bloody warning" to Indonesian President Megawati Sukarnoputri not to clamp down on militants.

"This is a message for her and all our enemies that, if they execute any of our Muslim brothers, we will continue this campaign of terror in Indonesia and the region," it quoted the JI operative saying.

Jakarta blamed JI for last October's Bali bombings, which killed 202, many of them Australian revellers in two nightclubs. Tuesday's blast came two days before the first verdict in trials for that atrocity is to be delivered.

Indonesian police said the methods used in the latest bombing resembled the Bali strike. More Australian police left for Jakarta on Wednesday to boost Australian federal police already in Indonesia and working with Indonesia on the Bali bomb.

One foreigner, a Dutch executive of Rabobank, was among those killed. Four Singaporeans, two Americans, two Australians and several New Zealanders were among 150 wounded on Tuesday. No Chinese was found among the casualties, according to the Chinese Foreign Ministry.

Confusion clouded the death toll, with Jakarta police saying up to 10 had died while Australia said the number killed had risen to 16 in an attack clearly intended to target foreigners.

International condemnation was swift. The United States offered Megawati help in bringing those behind the suspected suicide bombing to justice.

New Zealand Foreign Minister Phil Goff pointed the finger at JI as the likely perpetrators of the blast. "It's almost inevitable when you have a group like Jemaah Islamiah that sooner or later they will be successful. They tragically have been again on this occasion," Goff told Radio New Zealand on Wednesday.

Security above human rights

Chief Indonesian security minister Susilo Bambang Yudhoyono said a new approach to security in public places was needed to combat terror threats, the official Antara news agency reported.

"The government will impose these restrictions as we are determined to prevent the deaths of more victims. Their lives are worth more than the price of human rights," the Jakarta Post quoted Yudhoyono as saying.

In a first step to track down those responsible, police said they would issue a sketch of the owner of the car but did not say if the individual was a suspect in the blast.

"Police have obtained physical features from the (previous) owner of the car and we will issue a sketch based on that," Erwin Mappaseng, head of the criminal investigation department, told reporters.

Officials have said a suicide bomber probably caused the blast, which ripped through the lobby and set fire to dozens of cars and taxis. Windows in the 33-storey hotel were blown out.

Debris still littered the Marriott and two adjacent buildings on Wednesday. Hundreds of police had cordoned off the area and police forensic experts were due on the scene.

"This is a clear message that the war against terrorism in the region must be pursued without let-up," Philippine President Gloria Macapagal Arroyo told ASEAN finance ministers in Manila.

"Vigilance must become a way of life for the region even as we maintain normalcy in the course of work and business."

Indonesians were shocked by the bombing.

"This is sadistic. I bet they were anti-American," said Tambunan, a middle-aged man as he stared up at the Marriott's shattered windows. Twisted metal lay in front of the hotel. The shells of two burned-out cars had yet to be removed.

Security has already been stepped up in Jakarta, with guards checking cars before they entered some building compounds.

The Australian school said security had been raised to the highest level at its two campuses in Jakarta, but the atmosphere was relaxed and pupils were arriving as usual.

Jakarta warned recently of more attacks by Jemaah Islamiah.

"The scale, style, the target and the timing all point to JI," said one security expert in Jakarta, referring to the Bali bombing verdict and Tuesday's treason hearing of Abu Bakar Bashir, accused leader of the Jemaah Islamiah.

Australian Prime Minister John Howard urged Australians in Jakarta to take care and recommended other Australians to avoid any non-essential travel to Indonesia.

(Agencies via Xinhua)