However, the Chandigarh-Manali National Highway 21, which was closed for vehicles near Patlikuhl, 20 km before Manali, was reopened.
Officials said roads in the higher reaches of Kinnaur, Shimla, Chamba, Mandi, Kullu and Sirmaur districts were severely hit by heavy snowfall and work was on to reopen these.
"The road link to Narkanda, Rohru and Chopal (from Shimla) is likely to be restored by tomorrow (Wednesday)," Shimla Deputy Commissioner Dinesh Malhotra said.
The Himachal Pradesh Road Transport Corporation (HRTC) has been operating buses for Rohru and Chopal areas from Shimla via Vikasnagar in Dehradun district in Uttarakhand.
Officials said vehicular traffic on the Shimla-Theog-Rohru road via Kharapathar remained shut for the fifth day as a thick layer of snow covered the road.
Buses from Shimla town to Rampur and Kinnaur district were plying via Dhami.
The internal roads in the tourist resorts of Shimla, Manali and Dalhousie were too slippery for traffic after the snowfall.
Although the Shimla Municipal Corporation has cleared snow on Cart Road and some VIP roads, most of the other roads have not been cleared yet.
Seven people lost their lives in the state in the past four days due to snowfall, officials said.
Due to slippery condition of roads and pathways in Shimla, more than 30 people, most of them tourists, were injured, police said.
Keylong, district headquarters of Lahaul and Spiti, was the coldest town in the state with a low of minus 17 degrees Celsius.
The night temperature in the state capital was 1.6 degrees Celsius Monday, while popular tourist resort Manali saw a low of six degrees below freezing point. Kalpa in Kinnaur district was minus 9.2 degrees.
The minimum temperature at Dharamsala, the venue of the fifth ODI between India and England on January 27, was 4.2 degrees Celsius.