Updated

Authorities in southern France have detained a Moroccan man they said stabbed a woman and her three daughters Tuesday at an Alps resort, briefly sparking some panic in a nation reeling from its third major attack in 18 months.

Jean-Marc Duprat, a deputy mayor for the town of Laragne-Monteglin in the Hautes-Alpes region, says the mother and her girls, aged 8, 12 and 14, were vacationing at a nearby resort when a man from a neighboring apartment attacked them Tuesday morning as they ate their breakfast.

All four were expected to recover, the deputy mayor said.

Duprat initially said the man was upset that the girls were wearing shorts and T-shirts. He later said that did not appear to be the case and that the attacker's motive was not known.

"At this time, we don't have a firm answer," Raphael Balland, prosecutor for the region, told reporters.

Balland said the attacker, who was on vacation with his wife and children, was brandishing an 3-inch, folding knife.

The youngest girl, who was the most gravely wounded, was out of danger following surgery at the hospital in Grenoble, Duprat said. Her mother and her two sisters were recovering at the hospital in Gap, a town closer to where the violence occurred.

Laragne-Monteglin is 110 miles northwest of Nice, where a Tunisian man killed 84 people on July 14 by driving a truck through a holiday crowd on Bastille Day.

The July 14 carnage has deeply upset a country still reeling from the Nov. 13 attacks in Paris, which killed 130 people and a separate January 2015 Paris attack that targeted journalists at the satirical magazine Charlie Hebdo and Jews at a kosher supermarket.

Hours after the knife attack, gendarmes evacuated a hotel north of Avignon after a man armed with a knife barricaded himself in his room and refused to pay his bill. An official close to the investigation said there were unconfirmed reports the man had been seen with a suspicious parcel with wires showing. The official was not authorized to speak on the record as the situation was ongoing.