Hundreds of thousands of Acehnese massed in the provincial capital, Banda Aceh, yesterday, in the biggest separatist rally of Indonesia's history.
As they did so scores of prisoners escaped from prisons in Aceh.
The official news agency, Antara, said 100 prisoners broke down the front gate and escaped from prison in the capital. Fifteen later returned.
Security forces, whose years of brutal rule in the province are blamed for the growing separatist movement, were conspicuous by their absence as wave after wave of Acehnese poured into Banda Aceh city centre and towards its main mosque, shouting "Independence" and "Referendum".
Asked in a weekend interview about the chances of Aceh breaking away, the regional autonomy minister, Mr Ryaas Rasyid, said: "I think 50-50. Psychologically, [the rebels] have been very, very successful in internalising the spirit of referendum among the people."
And that success was underlined yesterday when, by some counts, up to a quarter of the population of Aceh poured into the city, on the northern tip of Sumatra island. Some estimated the crowd was close to a million while more conservative estimates put it at about 500,000.
But even the smaller number made it the largest independence protest in the history of Indonesia, home to the world's fourth-biggest population. The province of East Timor voted overwhelmingly for independence in an August ballot, sparking a wave of violence and destruction from pro-Jakarta militias.
In another prison incident, a group of people travelling in 20 trucks started a fire at the Jantho prison, allowing 70 convicts to escape. Two prisoners refused to leave, Antara said.
The East Timor vote has fuelled the demands for an Aceh referendum, but Indonesia's chief military spokesman rejected the calls.
"The demand for a referendum is not realistic," Maj Gen Sudrajat said. "Aceh is a part of Indonesia. So Aceh is managed by Acehnese people together with the Indonesian people."