The U.S. government this week arrested several U.S. nationals linked to the mysterious February break-in at North Korea’s embassy in Madrid, a statement by a lawyer representing the accused confirmed on Friday.

A statement carried on the website of Free Joseon — the group that last month claimed responsibility for a raid on the DPRK embassy in the Spanish capital — expressed “dismay” at the decision.

“The U.S. Department of Justice has decided to execute warrants against U.S. persons that derive from criminal complaints filed by the North Korean regime,” Ambassador Lee Wolosky, speaking on behalf of the group,