AURILLAC, France (AP) — A unusual attack by bees in the French town of Aurillac has left 24 people injured, including three who were in critical condition but have since improved, according to local authorities.

Passersby were stung over a period of about 30 minutes on Sunday morning, according to the Prefecture of Cantal, in south-central France. Firefighters and medical teams were rushed to the scene to treat the victims, while police set up a security perimeter until the bees stopped their attack.

The three people in critical condition were evacuated to a local hospital. Pierre Mathonier, the mayor of Aurillac, told French broadcaster BFM TV on Monday that their condition has improved.

One of them was a 78-year-old person who had to be resuscitated after cardiorespiratory arrest and is now in stable condition, he said. The two others "are in good health," he added.

According to the mayor, the incident may have been related to Asian hornets threatening a beehive that had been installed on the roof terrace of a downtown hotel more than a decade ago. He said that this had likely caused the bees to become aggressive.

Mathonier said that the beekeeper has removed the beehive and relocated it outside of the town.

Lt. Col. Michel Cayla, in charge of the local fire services, said that he had never experienced such an attack. He said the victim who was in cardiorespiratory arrest had to be resuscitated in the fire department's ambulance.

"In terms of the number of victims, the panic among the people and the severity of some of the injuries, it was impressive," he told broadcaster TF1.