ANTIBES, France — Flash flooding around the French Riviera has killed at least 16 people, some drowned in a retirement home and others trapped in cars and campsites. Torrents of muddy water inundated buildings, roads and railway tracks, disrupting movement along the Mediterranean coast Sunday.

Residents of the picturesque and touristy region, stunned by the ferocity of the brief downpour Saturday night, described it as the worst flooding they’d ever seen. It was so dramatic that it prompted President Francois Hollande to pay an emergency visit Sunday to promise government aid for victims.

Helicopters patrolled the area and 27,000 homes were without electricity Sunday after rivers and streams overflowed their banks and fierce thunderstorms poured more than 6.7 inches of rain on the Cannes region in two hours Saturday night. That is the equivalent of two months of rainfall for the region, local radio France Bleu-Azur reported.

Hollande said the overall death toll by midday Sunday was 16, with three still missing. Government officials had given conflicting reports about casualty figures earlier in the day.

“It’s not over,” Hollande said, visiting the flood-stricken retirement home in the town of Biot and meeting with emergency workers.

He expressed condolences to families of victims and urged residents to remain cautious, especially on the region’s roads, many of which remained impassable Sunday. He promised aid for residents hit by the flooding and lamented serious damage to local stores and other businesses.

Some residents criticized authorities for not doing more to prevent flood damage in the region. Local firefighters and meteorologists said the amount of rain was unusual for the region this time of year, but were especially shocked by the intensity and speed of Saturday’s storm.

People were found dead in the towns of Cannes, Biot, Golfe-Juan and Mandelieu-la-Napoule in the southeast, the president’s office said.

Three elderly people were killed in the retirement home, Hollande said. Three others were found dead in their car after entering a flooded tunnel, authorities in Golfe-Juan said. Interior Ministry spokesman Pierre-Henry Brandet said the dead included victims who had been trapped in a parking lot and campsites as well.

Winds and rain whipped palm trees along the famed Croisette seaside promenade in Cannes in images shown on BFM television. Some cars parked near Cannes shore were swept away and overturned by high waves.

In nearby Antibes, campsites along the Brague River were suddenly inundated with muddy water. Cars overturned and roads were slick with mud.

Several trains were stopped because of flooded tracks, and traffic remained stopped along the Mediterranean coast between Nice and Toulon on Sunday morning, according to the SNCF rail authority. Several roads in the region were closed, including those reaching Cannes, which was particularly hard hit.

The flooding also disrupted a French league soccer match in Nice, forcing the stadium to shut down in the middle of play.

Hundreds of emergency workers were involved in rescue efforts, helped by clear skies around the region Sunday.

Pope Francis offered his prayers for the victims during his weekly Sunday blessing from St. Peter’s Square.

“We express our nearness to the hard-hit populations, including with concrete forms of solidarity,” he said.

The ANSA news agency said that several trains that were halted by the floods were carrying hundreds of Italian pilgrims to or from the shrine at Lourdes. The Italian group Unitalsi, which transports the sick to the shrine, said all the pilgrims on board were fine.