FILE PHOTO: A Spanish National Police car is seen outside the North Korea's embassy in Madrid, Spain February 28, 2019. REUTERS/Sergio Perez/File Photo

SEOUL (Reuters) - A break-in at the North Korean embassy in Spain in February was “a grave terrorist attack”, a representative from North Korea’s foreign ministry said on Sunday in the North’s first official comment on the incident.

The foreign ministry representative also called for an investigation and said North Korea was closely watching rumors that the U.S. Federal Bureau of Investigation (FBI) and an anti-North Korea group were behind the raid.

However, North Korea stopped short of blaming Washington directly and asked Spanish authorities to conduct the investigation in a responsible manner.

“We will wait for the result in patience,” the North’s state-run KCNA news agency quoted the representative as saying.

KCNA said an armed group assaulted its embassy in Spain and bound, beat and tortured embassy staff and stole communication equipment.

“An illegal intrusion into and occupation of a diplomatic mission and act of theft are a grave breach of state sovereignty and a flagrant violation of international law, and this kind of act should never be tolerated over the globe,” the North’s foreign ministry representative said.

A mysterious dissident group, Cheollima Civil Defense, also known as Free Joseon, acknowledged on its website last week it was behind the Feb. 22 incident but said it was not an attack and that the group had been invited into the embassy.

On Monday, it said North Korean leader Kim Jong Un would be humiliated if he rejects calls for freedom.