By Gopal SharmaKATHMANDU (Reuters) -Heavy rains triggered landslides and flash floods blocking roads, washing away bridges and killing at least 22 people in the last 36 hours in Nepal, officials said on Sunday. Three people were killed in southern Nepal in lightning strikes and one person died in floods in Udayapur district, also in east Nepal, he said. Eleven people were washed away by floods and have been missing since Saturday, authorities said. Several highways have been blocked by landslides and washed away by floods, stranding hundreds of passengers, authorities said. Dharmendra Kumar Mishra, district governor of Sunsari district, said water flows in the Koshi River were more than double normal.