Shenzhen Airlines received threats against three of its flights on Wednesday morning, causing disruptions to its flight schedule, according to the airline's official micro blog.

The flights were ZH9866 in Nanjing, ZH9243 in Xi'an and ZH9889 in Beijing, and the threats were received between 8:00 and 8:33 am.

The airline company immediately returned ZH9866 to Nanjing, ZH9243 landed in nearby Guilin, Guangxi, and ZH9889 was delayed.

Police in the three cities are investigating the threats.