(Yicai Global) Dec. 31 -- Turkish Airlines has started flying from Istanbul to Central China's Xi'an, home to the historical Terracotta Army site, as its first second-tier city in China.

Turkish Airlines added its fourth mainland destination, following Beijing, Shanghai, and Guangzhou, to boost the total number of flights to 24 a week, Chinese aviation news website CAAC News reported. The Xi'an route will run on Airbus A330s three times a week, with hopes of increasing that to four next summer.

Turkish Airlines is eyeing more second-tier cities, including Hangzhou, Chengdu, Kunming and Xiamen, Serhat Gok, general manager of the Istanbul-headquartered firm's Shanghai office, said previously in an interview with Yicai Global. More flights to first-tier cities' airports, including Beijing's new Daxing International Airport, are also on the wish list.

Second-tier cities have smaller crowds than first-tier ones but Turkish Airlines hopes to attract more transit customers via its global network, said Gok. Some 60 percent of those who take the Shanghai route are transit passengers, he added.

Turkish Airlines started flying from Istanbul to Beijing in 1999. Its Shanghai route followed in 2000 and the Guangzhou one in 2011. The company currently has a fleet of 350 aircraft, traveling to nearly 320 destinations worldwide.

Editor: Dou Shicong, Emmi Laine