Jemaah Islamiyah (JI) leaders Abu Dujana and Zarkasi were arrested in June last year, dealing a severe blow to the group, and are being tried for terrorism.

Prosecutors in the two cases recommended that they be given life sentences if found guilty.

Both defendants were guilty of an act of terrorism, they told a Jakarta court in separate hearings on Wednesday.

The two defendants are not specifically charged over any attack, but JI is blamed for the 2002 Bali bombings, which left 202 people dead, and a series of other incidents.

Prosecutor Firman Syah said Zarkasi was the acting head of JI in 2004 and had held several meetings with Dujana and other JI members involved in a series of terrorist attacks in Indonesia.

Prosecutors also on Wednesday sought jail sentences of between 12 and 14 years for four other militants accused of being JI members, Arif Saifudin, Taufik Masduki, Aziz Mustofa and Nur Afifuddin.

Prosecutors said they were accused of violating anti-terror laws by 'intentionally providing assistance and facilitating a terrorist by withholding information'.

JI was previously believed to have links with Al-Qaeda, but security analysts now believe the organisation is isolated.

The trials will resume on April 2. -- AFP