Five candidates are competing to become governor of Aceh, the top post in the province on the northern tip of Sumatra. They include two former leaders of the now-disbanded rebel Free Aceh Movement, which signed the peace deal with the Indonesian government in 2005.

The current governor, Irwandi Yusuf, who is seeking a second five-year term, is a former rebel, as is his most formidable challenger, Zaini Abdullah.

Thirteen people were killed in attacks in the run-up to the election. Most of them were migrant workers from other parts of Indonesia.

Yusuf blamed his opponent for the violence, but Abdullah has denied the accusations.

The attacks have added to fears of a renewed violence following the election.

The peace deal between the rebels and the central government was closed in the wake of the 2004 Indian Ocean tsunami, which killed 170,000 people in Aceh.

The province's more than three million residents are also casting ballots for numerous district and mayoral officials. Results are expected by April 15.

Aceh is allowed to impose Islamic law as part of the autonomy scheme agreed with the central government. The rest of the country, which has a Muslim majority, practices a moderate form of Islam.

Its long war against Indonesian rule claimed 15,000 lives.

ncy/tj (dpa, AFP)