Indonesian police say a man they arrested on Tuesday and who is said to be a key leader of regional militant group Jemaah Islamiah took part in the Bali bombing.

Mukhlas, alias Ali Gufron, was arrested in Central Java and is believed to be the most senior figure detained so far in connection with the attack.

The chief investigator into the Bali blasts, I Made Mangku Pastika, said Mukhlas admitted to taking part in meetings in the summer at which the attack was planned.

Mukhlas is the brother of another suspect, Amrozi,

Mr Pastika said Mukhlas had also admitted to being a member of JI.

The report ties JI even closer to the 12 October bombing, which killed at least 180 people. The group is already seen as the prime suspect behind the attack by several governments.

JI is believed to be agitating for a pan-Islamic state across South-East Asia and is linked by the US to al-Qaeda.

Family connections

Mukhlas is the elder brother of another man in custody in connection with the Bali bombing - Amrozi.

Mr Pastika said last week that Mukhlas had taken over as operations chief for JI, although he appeared to qualify that assessment on Thursday, pointing out that JI members do not have a concept of hierarchy.

Mukhlas was arrested along with eight other people, including his wife, close to the Central Javanese town of Solo on Tuesday.

It was not clear how many of the others detained are implicated in the Bali blast.

Indonesian police will be hoping that Mukhlas can give them an insight into the operations of JI, and also point them in the direction of other members of the group.

A man known as Hambali, who is believed to have been the operations head of JI before Mukhlas, is still at large. He is wanted by several governments in the region in connection with a string of bombings over the last two years.