North Korea’s capital and surrounding areas experienced an “abnormal climatic phenomenon,” the official Korea Central News Agency (KCNA) said on Friday, echoing a flurry of state television reports from prior days.

The conditions, which in photos appeared to be a thick fog, were described as “unprecedented” according to North Korean weather experts quoted by state media.

“An abnormal climatic phenomenon was observed in south of the central west coast including Pyongyang City and some areas of inland of the DPRK from Tuesday dawn to Thursday morning,” Friday’s KCNA report said.

A “high density of fine dust” was blamed for