Jakarta – Indonesia threatened yesterday to resume full combat operations in restive Aceh province as fresh clashes between troops and rebels killed four people, putting yet more strain on a shaky peace pact.

Security Minister Susilo Bambang Yudhoyono said the military chief would present a battle plan to President Megawati Sukarnoputri next week – in case it should be needed – after what he said was a snub from the Free Aceh Movement (GAM) to discuss the December 9 peace pact.

"We are seeking a way out so that this so-called wide-scale military operation will not happen. But if peace efforts ... fail, the military solution is inevitable," Mr Susilo told reporters.

The warning to GAM follows the withdrawal to Aceh's capital of 100 peace monitors following attacks on their posts across the region on the northern tip of Sumatra island earlier this week. Both sides have traded accusations over who is to blame for the renewed clashes, the threats against the monitors and the heightened suspicions over political motives.

Mr Eddy Fernandy, a military spokesman in Aceh, said there were at least four clashes between troops and rebels yesterday which left two soldiers and two GAM fighters dead.

Mr Susilo showed reporters a letter from the Geneva-based Henry Dunant Centre, which brokered the agreement, that said the rebels had refused to attend a meeting proposed by the government to try to sort out problems. He said Ms Megawati would review the military plan and decide what to do next.

A leading Aceh-based GAM negotiator refused to comment, saying any response needed to come from Stockholm, where most of GAM's leaders live in exile.