A packed Air China flight bound for Seoul was forced to make an emergency landing in Shanghai on Saturday after a lithium battery inside a passenger’s carry-on luggage erupted in flames, filling the cabin with smoke. The blaze broke out aboard Flight CA139, which had departed Hangzhou Xiaoshan International Airport at 9:47 a.m. local time with 160 passengers and crew headed to South firrKorea’s Incheon International Airport, according to statements from the airline and Chinese state media. Air China said in a post on Weibo that “a lithium battery in a passenger’s carry-on luggage stored in the overhead compartment spontaneously ignited.”