Three labourers were trapped after an under-construction tunnel collapsed in Bilaspur town of Himachal Pradesh's Panol district.
Bilaspur's Sub Divisional Magistrate R. Pathania said the accident took place at 8:20 pm last night.
"Three labourers had gone inside and got trapped accidently. Machines have been installed to supply oxygen to the trapped labourers," he added.
The tunnel is part of the Chandigarh-Manali National Highway. It is located at Kandrour between Bilaspur and Ghumarwin towns around 100 km from Shimla.