China revoked the license of a visa agency Wednesday which serves South Koreans, triggering speculations it was linked to the decision to deploy a US missile defense system.

The South Korea-based Chinese company, China Maofa International Travel Service, is the exclusive agent of South Korean businesspeople who apply for multi-entry visas, the Chosun Ilbo newspaper reported Thursday.

Numerous South Koreans were reportedly refused long-term business and exchange-based visas following the decision to deploy the Terminal High-Altitude Area Defense (THAAD) system in South Korea, which had raised concerns that China was retaliating against the US ally, the Yonhap News Agency reported on Thursday.

South Korea's foreign ministry said it will "analyze" whether the move is related to Seoul's deployment of THAAD, ministry spokesman Cho June-hyuck said at a regular briefing.

Cho was quoted by Yonhap as saying that the ministry is in touch with the Chinese Embassy in South Korea over the matter.

In the meantime, South Korean duty-free stores are also worried about losing their Chinese customers, as South Korean authorities plan to implement a purchase quota policy this year, news site sina.com reported on Wednesday.