Indonesia's high court has upheld a 2 1/2 year prison sentence for accused terror chief Abu Bakar Bashir for conspiracy in the 2002 Bali nightclub bombings, a court official said.

Lawyers for Bashir, whom Australia and the United States allege is the spiritual head of the al-Qaeda-linked Jemaah Islamiah terror group, said they had yet to be informed of the decision but would appeal to the Supreme Court. Bashir was convicted in March of conspiracy in the Bali bombings.

Husein Kasing, a spokesman for Jakarta High Court, said judges had rejected the appeal filed by Bashir after that verdict. The court, which convenes behind closed doors, reached its verdict on May 11, but did not immediately publicise it, as is customary in Indonesia.