North Korea confiscated five facilities owned by South Korea at a jointly operated mountain resort on Friday, and it called South Korea's president a "traitor" and accused him of defaming the North's most important holiday.
The unilateral seizures and harsh comments were indicative of the tensions that have been rising between the Koreas since a South Korean warship sank in a mysterious explosion on March 26.
North Korea has denied any involvement in the sinking, which killed 39 South Korean sailors. Seven seamen are still missing and presumed dead.
North Korea said it was confiscating five buildings at the Diamond Mountain resort — a spa, a cultural center, a fire station, a duty-free shop and a reunion center for families separated by the Korean War — to compensate for the losses it says it has suffered since South Korea suspended tours to the resort, which is in the North.