A Nepal police official says at least 13 people were killed and another 26 hurt when a bus slipped off a mountain gravel road and rolled down a hill for nearly 200 meters (650 feet). Police official Umesh Khadka said Tuesday that the bus plunged off the narrow road near Barkhetar, 200 kilometers (125 miles) east of the capital, Kathmandu. Villagers and police officers from nearby villagers were at the crash site but the wreckage was trapped between trees on a steep slope, making it difficult to pull out survivors. An army rescue helicopter and soldiers were also headed to the accident site. Bus accidents are common in mountainous Nepal and are generally blamed on poorly maintained vehicles and road conditions.