BEIJING — A magnitude 7 earthquake hit China's Tibet region on Thursday evening, killing at least 16 people, injuring 54 and collapsing hundreds of homes in the northern regional city of Nagqu, official media said. Search and rescue efforts continued following the collapse of at least 339 homes and 20 livestock sheds, the Nagqu media office said, citing city government officials. More than 1,600 people from the local county were deployed for rescue efforts. Supplies including 1,000 prefabricated housing units, around 3,000 tents and folding beds, as well as flashlights and winter clothing arrived in the region. China’s official news agency Xinhua said on Friday that communication in part of the region has been down. Local railway authorities have taken emergency actions to halt trains passing through the region. The earthquake also caused rockfalls that have forced local authorities to close a section of National Highway 317, allowing only emergency, rescue and official support vehicles through as crews worked to clear debris, according to Xinhua. Intermittent snows are expected in th