Indonesia ? Indonesia signed a peace agreement Monday with rebels in Aceh province who have fought for nearly 30 years for a separate state, lending a crucial boost to efforts at rebuilding the tsunami-battered region.

Under the accord, signed at a ceremony in Helsinki, the Finnish capital, the Free Aceh Movement set aside its long-standing demand for independence and agreed to immediately begin turning over its weapons to international observers, drawn mainly from the European Union. Disarmament is due to be completed by the end of the year.

In return, the Indonesian government agreed to revise electoral laws so Acehnese can form local political parties and nominate candidates for offices at all levels of government. Indonesia will significantly scale back its security force in Aceh, estimated at 35,000 soldiers and police officers. The government also agreed to notify observers before staging any military maneuver involving more than a platoon.

“There is always a time for rain to stop, and there is always a time for war or conflict to end,” said Indonesia’s justice minister, Hamid Awaluddin, who led the government’s delegation in Helsinki.

The agreement capped five rounds of talks mediated by Finland’s former president, Martti Ahtisaari.