Rochdale Old Road is closed in both directions outside Hooley Bridge Services due to a road traffic collision.
A number of emergency service vehicles are on the scene.
Transport for Greater Manchester first reported the collision at about 9:15 pm on Monday.
A tweet from TfGM read: "Rochdale Old Road is closed in both directions outside Hooley Bridge Services.
"This is due to an RTC.
"Local bus services are on diversion.
If you're heading this way, please seek an alternative route."
Local bus company, Rosso added: "Due to an ongoing police incident on Rochdale Road near to Jericho which has closed the road. We are having to divert our Trax.
"We will be diverting via Bury Bridge, Heywood and Queens Park Road in both directions.
"We apologise for any inconvenience caused."
Greater Manchester Police have been contacted for comment.
More to follow...