A 35 year-old woman is in hospital with "serious injuries" after a collision on the M4 last night, involving a car towing a horse box.
The incident happened at around 9pm on the westbound carriageway between junctions 36 and 37.
It involved a red Nissan Terrano towing a horse box and a grey Vauxhall Insignia. Occupants of both cars were sent to Morriston, Princess of Wales and University of Wales Hospitals.
The horse box became detached, forcing police to block the motorway while the horses were rounded up.
South Wales Police has confirmed the horses were "uninjured."