The Chandigarh-Shimla national highway was closed on Saturday following massive landslides, police said.
"The Chandigarh-Shimla highway has been closed between Tara Devi and Shogi towns due to landslides triggered by uninterrupted rain since early Saturday," a police official told IANS.
Traffic bound for Shimla has been diverted from Shogi, some 20 km from the state capital. The highway is a crucial link to remote Kinnaur and upper Shimla districts.
There was a long queue of vehicles on both sides of the highway, a witness said.
Being a weekend, there was a huge rush of tourists for Shimla and nearby places.
"Work is on to clear the landslides. The highway is likely to be reopened in the evening," the official added.