South Korea has turned down a local rescue group's request to visit North Korea to help the communist country manage a deadly collapse of an apartment building in May, a unification ministry official said Thursday.

The 23-story apartment building collapsed in Pyongyang on May 13, according to the North's state media. Improper construction and irresponsible supervision of the high-rise construction were to blame for the disaster, though the North did not elaborate on the death toll.

Last month, the Seoul-based Korea Rescue Association sought the government's approval to visit the North after receiving a request from Pyongyang's "Red Star General Bureau of Construction" for help.

"Nearly two months have passed since the accident, and there are some signs that the North has already begun a new construction project at the site. So we think it is not appropriate for the group to visit there for rescue operations," the official at the unification ministry said, explaining the reason for its disapproval.

The official also noted that the North's agency that filed for help does not appear to be "a substantial and reliable organization."

Despite persistent inter-Korean tensions, the Seoul government has often given the nod to civilian groups wanting to visit the North for humanitarian projects. (Yonhap)