UPDATE 5-Spanish judge to seek extradition of N.Korea embassy intruders -source

A Spanish judge plans to request the extradition from the United States of members of a group he suspects of forcing their way into the North Korean embassy in Madrid and trying to persuade an official there to defect, a judicial source said on Tuesday. The judge believes a group of 10 intruders identified themselves as human rights campaigners during the assault, according to a document of Spain's High Court. A few days later their leader contacted the U.S. Federal Bureau of Investigation (FBI) to pass on information about the raid, the document said.

The judicial source told Reuters the judge believes all the identified suspects went to the United States after the raid and that he would request their extradition to Spain, where they could face up to 28 years in prison. State Department spokesman Robert Palladino said the U.S. government was not involved in the raid, which Spanish High Court documents said involved a Mexican citizen who is a U.S. resident and a U.S. citizen, as well as South Korean citizens.

"The United States government had nothing to do with this," Palladino told a regular news briefing, stressing that the United States called for the protection of embassies, whichever country they belonged to. He referred questions about the investigation to Spanish authorities. The State Department did not immediately respond to a request for comment about the extradition request.

The FBI said in a statement it is "our standard practice to neither confirm nor deny the existence of an investigation," adding that the agency had a strong working relationship with Spanish law enforcement partners. Spain's Interior Ministry had previously said police were investigating an incident at the embassy on Feb. 22, but gave no details except to say that a North Korean citizen had been injured and that no one had filed a complaint.

A Mexican citizen who is a U.S. resident, identified as Adrian Hong Chang, led the group, the Spanish High Court said in the document, based on the investigation of the incident. The court identified the U.S. citizen as Sam Ryu. The group stole computers, hard disks and pen drives, it said. It was not clear how the court knew that Hong Chang had contacted the FBI.

Three of the intruders took an embassy official into the basement and encouraged him to defect from North Korea. They identified themselves as members of a group who campaigned for the "liberation of North Korea", the document said. The Washington Post reported earlier this month that a dissident organisation called Cheollima Civil Defense had carried out the raid. The paper quoted unnamed sources as saying last week that the group shared information about the raid with the FBI.

A source familiar with official U.S. government reporting on the incident said that while they were not 100 percent positive, U.S. government experts found it plausible that Cheollima Civil Defense, which also goes by the name Free Joseon, carried out the raid. The source did not want to be otherwise identified. FAKE GUNS, BALACLAVA MASKS

The Spanish court document gave a detailed account of the intruders' movements before as well as during the intrusion, including their stay in a hotel and purchases of knives, balaclava masks and fake guns. There was no immediate comment on the matter from South Korea's Foreign Ministry. Spain's Interior Ministry and Mexico's foreign ministry declined to comment.

The embassy raid occurred shortly before the Feb. 27-28 summit between North Korean leader Kim Jong Un and U.S. President Donald Trump in Hanoi. The Mexican, Hong Chang, said he had carried out the raid voluntarily and he did not identify his companions, the court document said.

Sung-Yoon Lee, a North Korea expert at Tufts University in the United States, said he was shocked that the names should have been revealed in the Spanish documents. He said this could put the lives of members of the group - including a U.S. citizen, a U.S. resident and citizens of a close ally, South Korea - at risk from North Korean reprisals. "It seemed clear to me that the FBI had initially taken the position that the intel assets the group had retrieved at the embassy warranted the protection of the identities of the group," he said.

"That the Spanish government has not redacted the names of the persons implicated is also quite shocking," he said. "Observing this extraordinary situation unfold, who in the future would collaborate with the United States government were they ever to come into possession of high-value intelligence on North Korea obtained illegally?”

The FBI declined to comment when asked about the risk of North Korean reprisals. According to the court document, the group kept embassy staff tied up for several hours and then searched the premises for arms before leaving, at which point they separated into four groups and headed to Portugal.

Hong Chang then flew from Lisbon to New York. In Spain the High Court has the power to investigate criminal offences, after which formal accusations are launched. (Additional reporting by Belen Carreno, Andres Gonzalez and Sabela Ojea in Madrid, David Brunnstrom and Mark Hosenball in Washington and Hyonhee Shin in Seoul, editing by Axel Bugge, Gareth Jones and James Dalgleish)