Emergency services were scrambled to a city centre street tonight and a police cordon was put in place.
Residents reported seeing up to five police vehicles and an ambulance in Sunbridge Road, Bradford, with part of the road cordoned off.
One businessman in the area told the T&A that he understood that a group of men had been fighting before one person fell to the ground, seemingly badly injured.
That account of events is currently unconfirmed.
The road was still closed at 11pm as inquiries at the scene continued.
Police are yet to release details of the incident through their media channels.