New Zealand’s military said it detected signs of an illegal ship-to-ship transfer involving North Korean goods during its monthlong patrol of waters near the Korean Peninsula.

A Royal New Zealand Air Force P-8A Poseidon aircraft patrolling the Yellow Sea and East China Sea “observed a possible ship-to-ship transfer of illicit goods,” Wellington’s military said in a statement Tuesday.

The air force also reported 35 “vessels of interest” to the U.N. and broadcasted eight “deterrence messages,” the statement said.

“The evidence captured of activities that were occurring in the … seas allows authorities to take action against ships that may