By Ju-min Park
SEOUL (Reuters) - South Korean police said on Friday they were investigating possible links between a knife attack on the U.S. ambassador to Seoul and the assailant's multiple visits to North Korea, as they also sought to charge him with attempted murder.
U.S. ambassador Mark Lippert needed 80 stitches after his face was slashed at a forum discussing Korean unification in the capital, Seoul, on Thursday.
The attack was carried out by a Korean nationalist, now under arrest, who said he was protesting against annual U.S.-South Korean military exercises that began this week.
Late on Friday, the Seoul Central District Court issued a detention warrant against the assailant, identified as 55-year-old Kim Ki-jong, an official at the court said.
The warrant, issued by courts when there are concerns over a suspect fleeing or tampering with evidence, allows authorities to hold a person for up to 10 days for questioning. Detention can be extended to 30 days if another warrant is obtained.
Investigators have established that Kim made seven visits to North Korea between 1999 and 2007.
"We are investigating whether there is any connection between the suspect's visits to North Korea and the crime committed against the U.S. ambassador," Yoon Myeong-seong, chief of police in Seoul's central Jongno district, told reporters.
Most South Koreans have never visited the secretive North. The two states technically remain at war under a truce that ended the 1950-53 Korea War, and a heavily armed border divides the peninsula.
Kim denied on Friday that his actions were connected in any way with North Korea, calling the suggestion "nonsense", and told reporters he had never been to the North.
"THE KNIFE OF JUSTICE"
According to South Korea's Unification Ministry, Kim planted trees near the North Korean city of Kaesong, close to the border, during his visits there. The ministry said it had authorized his visit requests at the time.
Kim also faces charges of assaulting a foreign envoy and obstructing business operations. Police raided his home and office early on Friday, looking for evidence of whether he also broke a state security law that bans supporting North Korea.
Police said they had found books believed to be published in North Korea and were looking into his motive for possessing them.
In 2010, Kim tried to attack the Japanese ambassador to South Korea by throwing a piece of concrete and was given a suspended jail term, according to police.
Kim was a member of the pro-unification group that hosted the Thursday forum.
North Korean state media has said the attack against Lippert was "deserved punishment" for the military drills, calling the assault "the knife of justice". South Korea's Unification Ministry condemned the statement as "senseless".
The South Korean government ordered increased security for diplomatic missions, including the U.S. embassy, and police said they were providing protection for Lippert.
Lippert was accompanied by a bodyguard when the attack took place on Thursday. Police were also present, although not at the request of the U.S. embassy or organizers.
The United States is South Korea's closest ally and maintains a military presence that includes 28,500 personnel. That has drawn protest and criticism from some in South Korea in the past but public opposition has eased in recent years.
Lippert is recovering in a Seoul hospital and has said he is in "good spirits".
Doctors at Yonsei University's Severance Hospital said Lippert was likely to remain there until early next week, when they planned to remove his stitches.
Lippert underwent surgery on Thursday for an 11-cm (4 inches) gash on the right side of his face and a puncture wound on his left wrist that caused nerve damage, which was repaired.
(Additional reporting by Christine Kim and Seungyun Oh; Writing by Jack Kim; Editing by Paul Tait, Tony Munroe and Mike Collett-White)