All the troops hit the deck or took cover. "Shall I shoot?" Eagle-eyes asked.
"No, don't," the special forces sergeant said. "Remember we're here to save the people, to protect the people. Check first."
Seconds later a paramilitary policemen had clearly decided he was sure the figures were rebels and, without warning, opened fire with a light machine gun.
The rat-tat-tat of live ammunition echoed off the surrounding houses for about a minute, until it was decided no one was returning fire. Several men stayed on guard while the rest ran towards the houses where the rebels had allegedly been hiding. But with nothing to shelter behind they soon stopped.
"We'll have to let them go," one soldier said. "Maybe we'll do better tomorrow."
Meanwhile a fire brigade truck had doused the flames at the school. Nothing was left in the office; papers for the final examinations hundreds sit this week were ashes. The exams will go ahead in tents.
Sensing the danger was ebbing, residents cautiously emerged out of their shuttered homes.
"I saw no one, I heard no one," said one woman who lived in the house next to the burning building. "We're all just too afraid to do anything, we're staying indoors unless we have to go out."
Like virtually everyone in Bireuen district, currently the most violence-wracked part of the province, no one wanted their names published. They are too scared.
"If they see my name in the paper they will kill me," said a woman who witnessed Monday's raid on the Madrasah Ibtidaiah Negeri primary school in Kroeng Baro village, 3km east of Bireuen.
"Especially because I think the perpetrators were [government] soldiers from the type of camouflage uniforms they were wearing."
Some people said the raiders -- who felled coconut trees and telegraph poles across the roads to thwart pursuers -- even confiscated their identity cards as additional intimidation.
"We've never seen anything like this before," said Nurdin Muhammad, "We don't know what to feel, what to do."
Gauging people's real feelings is hard. Most Acehnese give neutral answers or just shrug when asked which side they hope will win. But occasionally someone is a bit more forthcoming.
"We're afraid but only of the Indonesian soldiers," said a worker from the emergency room at the Dr Fauziah hospital in Bireuen. "They have brutalized us for so long the only solution is independence. Otherwise we will never have peace."
The woman in the cafe predicted the situation will deteriorate. "The army cannot allow this to continue," she said. "They are going to have to do something and I'm just scared to think what that might be."
Timeline: struggle for independence
1949: Aceh, the westernmost part of the Dutch East Indies, becomes part of independent Indonesia
1976: Free Aceh Movement (GAM) formed calling for independent Islamic state, but the level of activity remains low
1989: Libyan-trained GAM guerrillas revive resistance
1990 to 1998: Indonesian army designates Aceh a ``special combat zone,'' kills more than 2,000 civilians
1998 to 1999: Military rule lifted after Suharto's fall, but his successors do not make amends for human-rights abuses committed in Aceh
2000: Army targets human-rights groups, GAM levies ``war taxes,'' violence increases until ``humanitarian pause'' agreed in May
March 2001: Indonesian defense minister announces new offensive against GAM; guerrillas attack ExxonMobil gas fields; troops sent to Aceh