The US ambassador to South Korea has been attacked by a knife-wielding man shouting anti-war slogans during a public event at an arts centre in Seoul.

The ambassador, Mark Lippert, was assaulted during a breakfast conference on Thursday as he was preparing to give a lecture about prospects for peace on the divided Korean Peninsula.

The US embassy said Lippert was in stable condition after surgery at a Seoul hospital. Hours after the attack Lippert tweeted that he is “doing well and in great spirits”.

The suspect, identified by police as Kim Ki-jong, 55, was immediately apprehended at the scene. Police said he slashed Lippert on the face and wrist with a knife. Kim had a previous conviction for hurling a stone at the then Japanese ambassador to Seoul in 2010, police said.

“We have detained him and are investigating the cause of the attack and other circumstances,” said district police chief Yoon Myung-soon.

Sources told Al Jazeera that Kim is the head of a relatively small civic organisation that has been calling for peace and reconciliation with North Korea.

Read More: Aljazeera