A major operation is taking place in central Hamburg after a man with an axe threatened police officers, officials in the German city say.
Police say they shot and seriously injured the man, who is receiving medical attention.
Media reports say the incident took place near a fanzone for supporters of the Dutch football team.
The Netherlands are playing Poland in the city in the Euros later on Sunday.
A police statement said that a man threatened police officers with a pickaxe and an “incendiary device”.
According to local media reports, the attack took place at about 12:30 local time (10:30 GMT).
Rory Smith, the New York Times’s chief soccer correspondent in Hamburg, said the incident took place on the Reeperbahn, a main street and nightlife area in the city just a few hundred yards from the Dutch fanzone.
BBC Sport journalist Gary Rose, who is also in Hamburg, said preparations were going ahead as planned for the 15:00 match.
The stadium is about five miles from the city centre where the incident happened.
There are approximately 30,000 Dutch fans in the city, and probably a similar number of Polish, and there appears to be a good atmosphere ahead of the match, seemingly unaffected by the incident.