Indonesia's government has reduced a radical Islamic cleric's prison sentence by three months to mark the country's Independence Day.

Abu Bakar Bashir, the spiritual leader of the militant group Jemaah Islamiyah behind the 2002 Bali bombings, was sentenced to 15 years in prison in 2011 after being convicted of funding a terror training camp in Aceh.

He has been serving the sentence at Gunung Sindur prison in the West Java town of Bogor.

The West Java Justice and Human Rights Office said Bashir deserved the reduction because he has served one-third of his sentence.

It was the second three-month reduction he has received.

Indonesia has a tradition of reducing the sentences of prisoners on national holidays.