The eastbound junctions of 23 and 22 have been closed in both directions with live traffic updates predicting the busy stretch will not reopen until after 4pm.
A statement from National Highways said: “The M4 Prince of Wales Bridge in Gloucestershire is closed in both directions due to an ongoing police led incident.
“If this closure impacts on your planned route, please allow extra journey time. Plan ahead, you may wish to re-route or even delay your journey.”
Police are on the scene and have been diverting traffic before closing the stretch until further notice. The Prince of Wales Bridge links England and the cities of Newport and Cardiff in Wales.
The M48 Severn Bridge remains open in both directions.
This is a live blog. See below for the latest updates.
