A South Korean diplomat was slugged in the face in an unprovoked attack on a Manhattan sidewalk Wednesday night, sources said.

The 53-year-old victim was walking with a friend when he was randomly attacked by a man on Fifth Avenue near East 35th Street at about 8:10 p.m., police sources said.

Sources said the victim, who allegedly did not say anything to the assailant, showed his diplomatic ID during the attack.

The diplomat was hospitalized with a broken nose, sources said.

The alleged attacker fled on foot towards Sixth Avenue. No arrests were immediately reported.

Additional reporting by Larry Celona