JAKARTA  - Indonesian police suspect Malaysian-born extremist Noordin Mohammed Top may be behind Friday's deadly twin bombings as they sift through bomb-making material found in a hotel room "control centre".

Two bombs tore through a restaurant and car park in the Ritz-Carlton and JW Marriott hotels around 8:00 am (0100 GMT) as guests were having breakfast, killing at least nine people and wounding more than 40 others.

Police said the bombs were home-made and they suspected at least one -- the device used at the Marriott -- was triggered by a suicide bomber after a headless body was found at the scene.

A senior official said police had found a third, unexploded bomb in a room at the Marriott along with evidence that may prove a treasure trove for Indonesian investigators along with their Australian and US counterparts.

"The control centre was a room at the JW Marriott, room number 1808, where anti-terror police found explosive materials and an unexploded bomb," Djali Yusuf, a senior advisor to President Susilo Bambang Yudhoyono, told AFP.

The bomb was defused as police searched the hotel following the attack which killed seven people at the Marriott. Twelve people died in a bombing of the Marriott in 2003 which was blamed on the Jemaah Islamiyah (JI) terror network.

Police have not said who they believe was responsible for the attacks and no group has claimed responsibility, but senior sources in the counter-terrorism unit said they bore all the hallmarks of master bombmaker Noordin.

The former accountant is the chief ideologue of the JI's most violent wing and is wanted for his alleged role in several attacks including bombings of Bali night-spots that killed 202 people in 2002.

"There must be a link with Noordin Top. There's a big possibility. But we still need to investigate how far he is involved," a counter-terrorism officer said, requesting anonymity due to the sensitive nature of the investigation.

Unconfirmed reports in the Indonesian media earlier this week said police had raided an Islamic boarding school in Cilacap, Central Java, in search of Noordin but he was not there.

"If it was a suicide bombing, then it's certainly a possibility that this was done by Noordin's network," International Crisis Group terrorism analyst Sidney Jones said.

"Noordin is no longer acting in the name of JI. He's a splinter of JI," she said.

Jakarta police chief Wahyono said the bombs were similar in both of Friday's attacks.

He said the suspected suicide bomber at the Marriott had "disguised himself as a guest" but it was not clear if he was staying in room 1808.

Video from a security camera at the Ritz-Carlton aired on the TV One station showed a man with a backpack on his chest and wheeling a suitcase entering the hotel restaurant moments before the bomb exploded.

The man was wearing a suit and baseball cap and walked awkwardly into the restaurant about 30 seconds before the blast.

The flickering footage from the second floor of the luxury hotel showed the large open doorway to the restaurant erupting with glass, debris and smoke as the bomb was detonated inside.

People in the doorway are engulfed by the blast, while others dive for cover behind furniture and walls.

Since the last major terror bombing in the mainly Muslim country, in 2005, Indonesian police have won praise for rounding up hundreds of JI militants and foiling a number of plots.

Three of the militants convicted of the 2002 Bali bombings were executed last year. Al-Qaeda-inspired extremists sympathetic to JI vowed to launch a wave of attacks in revenge for the execution of their "martyrs".

But Indonesian President Susilo Bambang Yudhoyono said Friday's attacks could also be linked to his re-election last week.

"This morning I heard from several parties who have an unsettling theory that this terror act is related to the presidential election," he said, while adding that it was too early to say who was responsible.