German Chancellor Gerhard Schroeder has become the second European leader to fall victim to harmless attack today.
Purple powder was thrown at British Prime Minster Tony Blair in the Commons while Mr Schroeder was slapped in the face during a campaign rally.
The Chancellor was signing autographs for a group of newcomers to his Social Democrat party in Mannheim when a man dressed in a suit struck him.
Four bodyguards tackled the man, later identified as an unemployed 52-year-old. He was detained and questioned for three hours before being released. State prosecutors are preparing assault charges.
Mr Schroeder expressed concern over what could have happened if the man was armed, his spokesman said.
Mannheim police said the man was released because they had no grounds to hold him. He refused comment on his motives.
Mr Schroeder's popularity has fallen because of cuts in unemployment benefits.
Witnesses quoted in media reports said Mr Schroeder made a tapping motion on his forehead - appearing to suggest the man was mad - and went on signing autographs before speaking.
Ironically, the Chancellor is due to meet the British Prime Minister later today. Mr Blair was speaking the Commons this morning when a powder paint ball was thrown from the VIP gallery, hitting him on the shoulder.