A man has died and two others have been injured in a knife and hammer attack on a street in central Paris, reports the BBC.
The attack occurred on Quai de Grenelle, near the Eiffel Tower, shortly before 21:00 local time (20:00 GMT) on Saturday.
A 26-year-old French national known to security services has been arrested and anti-terrorism prosecutors have opened an investigation.
Officials confirmed that the man killed was a German national.
France's interior minister Gérald Darmanin said the victim, born in 1999, was with his wife when he was attacked and fatally stabbed.
He said the wife's life was saved by the intervention of a taxi driver and that the suspect fled across a nearby bridge spanning the River Seine.
The man then attacked two more people, hitting one in the eye with a hammer, the minister said.
The suspect was then Tasered by police and arrested on suspicion of assassination - defined in French law as pre-meditated murder - and attempted assassination in relation to a terrorist enterprise.