Motorists are being advised to find an alternative route after police closed the A647 from Halifax to Queensbury through Boothtown in the early hours of the morning.
Calderdale Council tweeted about the road closure near the junction with Claremount Road, following the 'police incident."
It said: "The road isn't expected to open until later in the morning.Please find an alternative route."
The AA also reported that the Queensbury Road both ways from Ploughcroft Lane to Swales Moor Road had been closed since 3.30am this morning.
It is likely to be closed into the rush hour.