BBC Correspondent Jonathan Head reports from Lhokseumawe

The head of the Indonesian armed forces, General Wiranto, ordered the action after riots in several towns left at least one person dead and several injured.

Angry crowds burned and stoned shops for two days in the town of Lhokseumawe after a brief clash at a troop withdrawal ceremony on Monday.

Hundreds of reinforcements have been brought in to restore order and to prevent the rioting from spreading.

Separatist movement

Two days of rioting has damaged much of the town's commercial centre

There has been widespread public anger in Aceh over revelations of human rights abuses carried out by the Indonesian army as it tried to put down a separatist movement.

Insults were traded between local youths and the departing troops, and an angry mob went on a rampage, reducing the commercial heart of the town to ruins.

Investigators have found a number of mass graves in the province

Heavily armed soldiers are supervising a clean-up of the debris, and military checkpoints are stopping vehicles to search for possible looters.

There has been a rising tide of public anger in Aceh at human rights violations committed by the Indonesian army over the past nine years.

Mass graves

In a more open atmosphere prevailing since the fall of former president Suharto, dozens of Acehnese have testified about rapes, torture and killings at the hands of Indonesian soldiers.

Human rights groups have already begun digging up skeletons in several mass graves in the province.

Riots were triggered by bitterness towards the Indonesian military

A BBC correspondent in Lhokseumawe says some local residents say the rioting was deliberately provoked by the army to justify keeping its troops in Aceh, but that will be difficult to verify.

Evidence already found of military involvement in the Jakarta riots in May will give credence to such claims.