Crews are clearing roads in a town in the Italian Alps which was swamped by a mudslide after a mountain stream burst its banks following heavy rain.

Rescuers had also been searching for people possibly missing after the mudslide sent water and debris pouring into Bardonecchia, near Turin in the Val di Susa valley, but authorities said all residents had been accounted for.

One witness video showed a huge wave of dirt and debris toppling a gate and residents running away as the muck rushed down a street late on Sunday, and others showed thick mud coursing through the river banks that pass through the town.

Piedmont regional governor Alberto Cirio said there were no victims and that five people initially believed to be missing had been accounted for.

In a Facebook post, he said damage was significant and that he had already asked the national government for help.

Civil protection crews were en route to remove the debris from roads and to check the situation with the Frejus River, which was primarily involved, he wrote.

In a social media post, firefighters said crews had rescued six people from an overturned camper overnight.

Bardonecchia, located at 4,265ft (1,300m), is a popular destination for both winter mountain sports and summer hiking, and several streams, creeks and tributaries feed into it including the Frejus, Melezet and Rochemolles.

On Sunday, the town of 3,000 residents was celebrating its patron feast day, St Hipolito, with activities and games taking place, and planned fireworks at night, according to the local tourism agency.