The prefect for the wider region, Seydou Traore, said about 70 trucks full of insurgents participated in the attack, and he estimated about 50 more had arrived since.

The insurgents are staying in groups of 20 or so trucks, parking discreetly under trees to avoid aerial bombardment, he said.

That’s not the only way the rebels are hiding from air power. The rebels are shutting down the roads to prevent civilians from fleeing. They are then mixing in with the population, even eating food at their houses.

From those fleeing, there were no reports of civilian casualties. There also were no reports that the rebel force had been significantly weakened from the bombardment, which came not only from jets but also from ground-strafing helicopters.

Niono is the next town in line for battle, if the Islamists continue their advance. The area is far from the type of desert warfare France may have been expecting: It’s crisscrossed with canals, packed with rice and onion fields and eucalyptus plantations, its farms surrounded on all sides by countless dikes, ditches and bridges.

In Bamako, Mali’s capital hundreds of miles away, there are rumors that the French are massing for a ground attack on Diabaly. Here, however, there is little sign of such preparations, though the prefect said appearances can be deceiving.

"Who said they are not here?" he asked. "They spent last night here. They are here, you just can’t see them."

As dusk fell, four French armored personnel carriers were seen heading toward Niono.

Ali Giundo, 30, fled his Diabaly home on Monday, riding his motorbike all the way south to Niono.

"The road is full of rumors of this village and that falling to the jihadists," he said.

When he arrived at Niono, the soldiers at the bridge, the first he’d seen the whole trip, asked for his ID but did not frisk him.

"The enemy may try to infiltrate us as regular civilians," warned Traore, whose office is just a few yards from the checkpoint. "This is not conventional warfare."