Police have discovered human remains on a motorway carriageway near Bristol and have shut parts of two motorways in both directions.

A number of drivers called the police and reported seeing something on the road between junctions 20 and 21 of the M4 at 6.40pm on Saturday.

Avon and Somerset police officers attended and found human remains, which they believe are of a man in his 40s.

This section of the M4, which is between Almondsbury and Awkley, has been shut in both directions. The M48 has also been closed both ways between junction 1 and the M4, and links from M5 to the M4 are also shut.

The closures, which are expected to cause significant delays in and out of Wales, are likely to remain in place until the early hours of Sunday morning, police said.

The force said: “Enquiries are under way to identify the deceased and notify next of kin, while an investigation to establish how the person came to be on the motorway continues.

“Police are keen to hear from anyone who was travelling along that stretch of the M4 and has any relevant information or dashcam footage.”

The road closures start on the English side of the Prince of Wales Bridge and the Severn Bridge.