A section of National Highway 317 in Sichuan province collapsed on Tuesday afternoon following a mountain slope failure, but no casualties have been reported, according to a statement released by local authorities.

The initial signs of danger emerged on Monday, when slope deformation was detected on the right bank of the Hongqi Bridge section of the highway in Maerkang city in Sichuan.

On Monday at 5:25 pm, potential risks were identified during a local inspection, Sichuan Daily reported. Upon discovery, the local authorities immediately activated an emergency response. Personnel from public security, transportation, and natural resources departments arrived at the scene for emergency handling. By 11:00 pm, all stranded vehicles had been evacuated, and warning signs were set up on-site to strictly control unauthorized entry, the report said.

Relevant departments also issued a traffic control notice to alert the public. Thanks to timely traffic control measures, no casualties were reported, the statement said.

The situation escalated on Tuesday. A video posted online shows that as the slope deformation intensified, it triggered a landslide, causing the underlying roadbed and the approach bridge to collapse. The collapse of bridge piers and decks has produced a large amount of smoke and dust.

Currently, there is no estimated timeline for the reopening of the highway, the statement said. All incoming and outgoing vehicles are required to follow the designated detour routes specified in the notice.