The landslide near Lachen at Suphu Chu has off the road connection.
Another landslide at Menchekyong has blocked the road here, they said.
A third landslide at Zema I, which is 2 km from Lachen has also been reported. Official sources said that it might take another 2-3 days for army personnel to clear the roads.
A landslide had also blocked the road between Chungthang and Lachung at Khedung. However, traffic on this road is likely to resume by tomorrow.