Many Wiltshire roads were grid-locked today after a three-vehicle smash led to the part closure of the M4.

The motorway was blocked between junction 14 and 15 in both directions after two heavy goods vehicles and a car were in collision.

The accident happened at around 5am between junction 15 at Wroughton and Membury services and there were tailbacks for several miles in both directions, two miles eastbound and four miles westbound.

The foreign driver of one of the HGVs was taken to Swindon's Princess Margaret Hospital with serious injuries. His condition is not yet known.

Eastbound traffic could not enter the M4 at junctions 15, 16 and 17 this morning, and a police diversion was taking drivers to junction 14 at Hungerford.

Westbound traffic could not enter the motorway at junction 14, but was clear to enter from junction 15 onwards.

A police spokesman explained that one lorry carrying paint was parked on the hard shoulder on the westbound side of the carriageway and was in collision with a second lorry driven by the foreign driver, approaching from the rear.

Following the collision, the second lorry careered onto the motorway and ended up on the eastbound carriageway, where it came to rest in the road. It was then involved in another collision with a car.

Three fire pumps and an emergency support vehicle were sent to the scene but fire officers stress that no dangerous chemicals were spilt.

One other driver was taken to hospital with minor injuries.

Inspector Steve Kellow, of Swindon Police, said: "There will be major congestion on the M4 near Swindon this morning. We expect delays for at least four hours, if not a lot longer."

Meanwhile, a train was derailed at the Filton junction near Bristol this morning which spilled a large quantity of diesel onto the tracks.

The locomotive of the train, which was transporting coal, ended up on its side after derailing on a set of points just before 2.30am near the A38, close to the Filton airfield, which is about five miles from the city centre. The driver was shaken but uninjured.

The derailment in Bristol came almost a month after two trains collided at Lawrence Hill station near the city centre.

Police said a foreign-registered lorry collided with a stationary HGV carrying household paint on the westbound carriageway before crashing through the central reservation and into the path of an oncoming car.

The foreign lorry driver sustained serious injuries in the accident and was taken to Swindon's Princess Margaret Hospital.

A Wiltshire Police spokesman said: "Diversions are and will remain in place for some time."