China has suspended Chinese tourists’ overland tours to North Korea amid escalating tensions on the Korean Peninsula.

A travel agency staff said the company received a notification from Chinese authorities on Tuesday night that China was temporarily halting tours to the North in consideration of the situation on the Korean Peninsula and for the safety of Chinese tourists.

The official said that all tours to the North departing from Dandong, Liaoning Province, have been suspended from Wednesday.

Chinese Foreign Ministry Spokesman Hong Lei, however, denied that the government intervened in the cross-border tour, saying Chinese travel agencies and tourists are voluntarily canceling trips to the North given the latest tensions on the Korean Peninsula.

A source familiar with North Korea affairs said whether it is official or not, China’s move to suspend overland trips to the North is unprecedented.