North Korea's official Korean Central News Agency said on Sunday that a "serious" accident occurred last week at a construction site in the capital, Pyongyang, that claimed lives, although no death toll was announced.

According to the report, a major rescue operation was undertaken that ended on Saturday, and officials have apologized and given their condolences to victims' families.

The unusual report said the incident occurred in Phyongchon district on Tuesday "as the construction of an apartment house was not done properly and officials supervised and controlled it in an irresponsible manner."

The report said one official said that the country's leader, Kim Jong Un, "sat up all night, feeling painful after being told about the accident."

It is unusual for the highly controlled North Korean state media to report any news that could be considered less than positive.

South Korea