During the blasting work, some pieces of rocks hit four labourers and injured them at the tunnel on Jammu-Srinagar national highway in the district this afternoon, a police officer said.
The injured have been shifted to district hospital at Udhampur for treatment, he said.
The police officer ruled out collapse of any part of the tunnel.
The 12-km-long Chenani-Nashri tunnel is being constructed by a foreign company on J-K highway and over 40 per cent of the tunnelling work has been completed.
