China’s spat with S Korea over the Terminal High Altitude Area Defense (THAAD) system has continued to escalate with a new ban on tourist groups Thursday. According to reports from the Chinese tourism industry, the Chinese ministry of tourism ordered travel agencies to stop selling S Korea travel packages.

The ban amounts to a form of economic sanctions on China’ s third largest trading partner, with Chinese tourists accounting for around half of S Korea’s more than $1 billion a month tourism economy. In response to a question on new restricitions, China foreign ministry spokesman Geng Shuang responded dismissively that he “had not heard of that situation.” Adding, though, that China’s opposition to the establishment of the THAAD system was very clear.