The US ambassador to South Korea is recovering from a knife attack in the capital Seoul.
Police have searched the offices of the anti-US activist who they say slashed envoy Mark Lippert while screaming demands for Korean reunification.
The attack on Mr Lippert, which prompted rival North Korea to gloat about "knife slashes of justice," left deep gashes as well as damaged tendons and nerves.
It also raised questions about security in a city normally seen as ultra-safe, despite regular threats of war from Pyongyang.
While an extreme example, the attack is the latest act of political violence in a deeply divided country where some protesters portray their causes as matters of life and death.
Mr Lippert, 42, is recovering well but still complaining of pain in the wound on his left wrist and a finger where doctors repaired nerve damage, Severance Hospital official Yoon Do-Heum said in a televised briefing.
Doctors will remove the 80 stitches on Mr Lippert's face on Monday or Tuesday and expect him to be out of the hospital by Tuesday or Wednesday. Hospital officials say he may experience sensory problems in his left hand for several months.
Police, meanwhile, searched the offices of the suspect, Kim Ki-jong, 55, for documents and computer files as they investigated how the attack was planned and whether others were involved.
Police plan to request a warrant for Kim's formal arrest, and potential charges include attempted murder, assaulting a foreign envoy, obstruction and violating a controversial South Korean law that bars praise or assistance of North Korea, Jongno district police chief Yun Myung-sung told reporters.
Police are investigating Kim's past travels to North Korea - seven times between 1999 and 2007 - during a previous era of inter-Korean cooperation, when Seoul was ruled by a liberal government.
Kim attempted to build a memorial altar for former North Korean leader Kim Jong Il after his death in December 2011, police said.
Kim, who has a long history of anti-US protests, said he acted alone in the attack on Mr Lippert.
He told police it was meant as a protest of annual US-South Korean military drills that started Monday - exercises that the North has long maintained are preparations for an invasion. Kim said the drills, which Seoul and Washington say are purely defensive, ruined efforts for reconciliation between the Koreas, according to police officials.
"South and North Korea should be reunified," Kim shouted as he slashed Lippert with a 10in knife, police and witnesses said.
Kim is well-known among police and activists as one of a hard-core group of protesters willing to use violence to highlight their causes.
Police did not consider the possibility that Kim, who has ties to the Korean Council for Reconciliation and Cooperation, which hosted the breakfast meeting where Mr Lippert was attacked, would show up for the event, according to a Seoul police official.
US ambassadors have security details, but their size largely depends on the threat level of the post. Seoul is not considered to be a particularly high threat post despite its proximity to the North Korean border. It's not clear how many guards Mr Lippert had, but they would have been fewer than the ambassadors in most of the Middle East.
Seoul's foreign ministry said it was the first time a foreign ambassador stationed in modern South Korea had been injured in a violent attack.
However, the Japanese ambassador narrowly escaped injury in 2010 when Kim threw a piece of concrete at him, according to police. Kim, who was protesting Japan's claim to small disputed islands that are occupied by South Korea, hit the ambassador's secretary instead, media reports said, and was sentenced to a three-year suspended prison term over the attack.
North Korea's state-controlled media said that Kim's "knife slashes of justice" were "a deserved punishment on war maniac US" and reflected the South Korean people's protests against the US for driving the Korean Peninsula to the brink of war because of the joint military drills.
US secretary of state John Kerry, in Saudi Arabia for meetings with regional leaders, said America "will never be intimidated or deterred by threats or by anybody who harms any American diplomats".