Dharamshala, July 30 -- As heavy rainfall caused landslides at various locations in Himachal Pradesh, the Mandi-Kullu stretch of Chandigarh-Manali National Highway (NH-21) remained blocked at multiple locations on Tuesday. The stretch was blocked at 4 Mile, 9 Mile (near Pandoh) and Dwara (near Aut). Due to the highway closure vehicles were stranded along the roadside at several locations, leaving hundreds of people stuck. The Mandi-Jogindernagar stretch of NH-154 was also blocked for hours due to a landslide near Lawandi bridge. Mandi-Kotli stretch of NH-003 also was blocked on Tuesday morning. As many as 357 roads remained blocked in Himachal on Tuesday, with 259 roads blocked in Mandi district alone. With the spells of heavy rainfall expected to continue in coming days, the India Meteorological Department's (IMD) Shimla office has sounded an orange alert of heavy to very heavy rainfall in Chamba, Kangra, Mandi and Kullu districts on July 30 (Wednesday). Four other districts will be under a yellow alert of heavy rainfall. According to MeT department officials, light to moderate rainfall is very likely at most places on July 30 and August 4 and at many places from July 31 to August 3. One or two spells of heavy rainfall are also expected at isolated places till July 31 and very heavy rainfall on July 30. During the last 24 hours, monsoon activity was active over the state. While light to moderate rainfall was recorded at most places, heavy to extremely heavy rainfall was observed at isolated places. The highest rainfall of 21 cm was recorded in Sandhole in Mandi district, followed by Mandi (20 cm), Pandoh (12 cm), Kataula (9 cm), Dehra Gopipur (7 cm)....