They say the plan was to strike during an Independence Day ceremony on 17 August, and declare an Islamic state.

The militants also planned to take over hotels and kill foreigners, they said.

The announcement came a day after three suspected militants were detained in the latest in a series of anti-terror raids.

Police said the men were linked to a militant training camp discovered in Aceh in February. Dozens of suspected Islamists have been detained since then and a number killed.