Businesspeople have begun to cancel plans to visit North Korea’s Mount Geumgang resort.

The cancellations come after a North Korean military spokesman threatened a strong military response against even the slightest hostile action at the resort in a statement issued Sunday afternoon. The statement is North Korea’s response to the killing of a South Korean tourist by a North Korean soldier at the resort last month.

According to the inter-Korean immigration office, two businesspeople canceled their visits to the North Korean resort on Sunday afternoon. On Monday morning, eleven out of 14 businesspeople holding reservations canceled.

As of Monday morning, 829 people were at Mount Geumgang, including 257 staffers and contractors of Hyundai Asan, the South Korean operator of tour programs to the North Korean resort. Ninety-one people left the resort Monday afternoon.

Hyundai Asan said of the 91 people, 60 were Chinese with Korean ethnicity who left the North because either their contracts with Hyundai Asan expired or they were on vacation.

The immigration office said the mass cancellations Monday morning were very unusual, adding that the North Korean statement might have had something to do with it.