Greek police said a French fan was stabbed and slightly injured yesterday in clashes between supporters of Olympiakos and Saint-Etienne ahead of their UEFA Cup match.
A police statement said the man was hospitalised with two stab wounds to the thigh. Three other French fans required first aid after being hit with bottles and sticks.
There were no immediate reports of arrests.
The clashes involved hundreds of rival supporters outside Karaiskaki Stadium, near Athens.