Thousands of demonstrators rallied in Indonesia's Aceh on Thursday in support of local leaders' bid to adopt a separatist flag as the staunchly Islamic province's official emblem.

A 3,000-strong crowd, including many women wearing the Islamic head scarf, waved the flag -- a white crescent and star on a red background -- during the protest in provincial capital Banda Aceh, police and witnesses said.

Soldiers and tanks were deployed as the Indonesian Interior Minister Gamawan Fauzi met local leaders to demand they reverse the local parliament's decision allowing use of the flag in the country's only province with Islamic sharia law. The flag was used by the now defunct Free Aceh Movement (GAM) which fought a 30-year separatist war against the Indonesian state until a peace deal was struck in 2005, and the row over the emblem is being seen as a test of the accord.

After the local parliament last month passed a bylaw allowing use of the flag, Jakarta, which must approve laws made locally, protested and has demanded the decision be reversed. Under Indonesian law the use of separatist flags is illegal.

But the provincial government, led by former rebel Zaini Abdullah who has vowed to implement stricter sharia law, insists that under the peace accord Aceh can use whichever emblem it likes.

At Thursday's demonstration, protestor Hendra Fauzi told AFP: "We have the right to decide our own flag... and this is a test of whether the government will stick to the accord."

It was the second rally in Banda Aceh this week in support of the flag.

More than 15,000 people died in more than three decades of unrest during the oil- and gas-rich province's separatist struggle. Sporadic politically-motivated violence continues in Aceh.

The 2005 agreement between Jakarta and the rebels, which grants special autonomy to Aceh such as the right to use sharia law, was also made in the spirit of rebuilding the area after the 2004 tsunami that killed tens of thousands in the province.