BEIJING - SF Airlines, the aviation branch of China's express giant SF Express, has just added its 45th all-cargo freighter plane, the company said Monday.

This is the fourth freighter added to the SF Airlines fleet this year, the largest all-cargo air freighter fleet in China's air express industry, SF Airlines said.

To date, there are 23 B757-200, 17 B737 and five B767 all-cargo freighters in the SF Airlines fleet.

Based in Shenzhen, SF Airlines focuses on providing air express and customized air freight services to SF Express.

With its nationwide and global network, SF Airlines has transported around 2 million tonnes of cargo since operations began in 2009.

China has seen a growing air express industry. In 2017, China transported 7.06 million tons of air mail cargo, a 5.6 percent increase year-on-year, said statistics from the Civil Aviation Administration of China (CAAC).