New Delhi, July 21 -- ATHENS - The couple were walking toward the entrance of the Acropolis Museum on Tuesday morning when a man approached with a knife. The woman, a Greek American, received wounds to her leg. Her companion's arm injuries were described by Greek police as more severe. Both were taken to hospital by ambulance. The Acropolis citadel above, which drew 4.6 million visitors last year, remained open throughout the morning without interruption.

Greek police detained the attacker at the scene. He appeared to have been suffering from psychological problems, according to a police statement, and had reportedly threatened several passersby before the stabbing, prompting a public alert. His identity and nationality had not been disc...