Authorities in Indonesia's restive northern province of Aceh say a senior rebel has surrendered to the army. Indonesia's tactics in the battle to suppress the rebels have come in for more criticism from human rights organization.

A spokesman for the Indonesian army says the man who surrendered, Ibrahim Syafei, was a regional leader in the western part of the province for the Free Aceh Movement, which is known as GAM.

Indonesia has been trying to defeat the separatist movement in the resource-rich province for more than a quarter of a century. Jakarta renewed its military operations six months ago after a cease-fire broke down.

The military says the campaign is going well, and that more than 1,000 GAM members have been killed and nearly 2,000 have surrendered. But political analyst Kirsten Schulze in Jakarta questions how effective the campaign has been in damaging GAM's core support.

"They've done some damage to the GAM structure, but I think it is fairly safe to assume that not all the people killed and arrested who are allegedly GAM, are really GAM," she said. "And if that's true, the Indonesians haven't done as much damage to the GAM structure as they like to think."

She says that although Mr. Syafei is a senior civilian official, the real power in GAM rests with the rebel troops and the leaders in exile in Europe.

It is almost impossible to get a clear picture of what is happening in Aceh. The Indonesian authorities have placed heavy restrictions on access for journalists and other aid agencies. That policy came in for heavy criticism earlier this week from the international group Human Rights Watch.

The organization accuses both sides of human rights abuses in Aceh and says that both are attempting to muzzle the media to keep the truth hidden.

Allegations of human rights abuses in Aceh are nothing new. Observers estimate that more than 13,000 people have died in the past 28 years, most of them civilians. Other nations have voiced criticism, but many governments fear that giving in to separatists in Aceh could risk the disintegration of Indonesia and chaos in Southeast Asia.