Pyongyang, March 31 (IANS): North Korea has described a break-in at its embassy in Spain in February as a "grave terrorist attack".

In its first official comment, Pyongyang called for an investigation and said it was closely watching rumours that the Federal Bureau of Investigation (FBI) had played a role, the BBC reported on Sunday.

On Wednesday, Cheollima Civil Defense - a self-styled human rights group - which is committed to ousting North Korean top leader Kim Jong-un, claimed to be behind the raid.

The group took computers and data and said it gave its evidence to the FBI - US intelligence agency.

At least two international arrest warrants have been issued for the main suspects.

The break-in occurred on February 22, days before the second summit between US President Donald Trump and Kim in Hanoi, Vietnam.

Three of the intruders were identified as Adrian Hong Chang, a Mexican who lives in the US, Sam Ryu of the US, and South Korean Woo Ran Lee.

Sources close to the investigation reportedly told Spanish newspaper El Pais that the operation was planned perfectly, as if by a "military cell".

The attackers seemed to know what they were looking for. Spanish authorities suspect US intelligence agencies and their allies could have been involved in the attack, according to newspapers El Pais and El Confidencial.

El Pais even reports that two of the group members have links to the US Central Intelligence Agency (CIA).

The US has denied any involvement in the raid.