A South Yorkshire police spokesman said: “Officers are currently dealing with an incident on the A19 St George’s Bridge in Doncaster.
“Police were called about concerns for a man on the bridge at about 11am this morning, Tuesday 10 May.
“Specially trained officers are currently at the scene and drivers are advised to avoid the area while the incident is dealt with.”
They did not comment on claims that the man has been threatening to jump from the bridge.
A police car was seen driving on to the bridge at around midday. Another car is stationed at the entrance to the bridge, which is closed off with cones, and an officer is directing traffic.
The road currently remains closed between York Road roundabout and St George’s roundabout and traffic jams are building up around the area. Bus passengers are also being warned of delays.