Guwahati, July 30 (IANS) The rail connectivity between southern Assam, Tripura, Mizoram, Manipur and the rest of the country has remained affected for the past week after heavy rainfall damaged railway tracks along the strategically important Lumding-Badarpur Hill Section, officials said on Thursday. "Due to heavy rainfall, the soil beneath two of the three railway tracks near New Harangajao station has subsided over a stretch of around 300 metres. As heavy rain and inclement weather continue to persist, restoration work has also been hampered," the official said. Consequently, several trains operating along the Lumding-Badarpur Hill Section have been rescheduled, cancelled or regulated, the official said. The four-month monsoon period, from June to September, often causes extensive damage to railway tracks, embankments, bridges and other railway infrastructure due to landslides, waterlogging and erosion, particularly in the mountainous terrain of Dima Hasao district.