A horse has been shot dead after running onto the M25.

A number of horses escaped onto the motorway at around 6am this morning and while they were herded back, one broke free again at about 1.20pm.

Armed police officers took the decision to shoot the animal, after sedation attempts failed.

The road was reopened at 2.15pm but the horse caused 12 miles of tailbacks - stretching from the Dartford tunnel back to the Orpington turn-off of the M25.

A spokeswoman for Essex Police said: "The horses were herded off the highway while officers attempted to locate the owners. One horse got loose again and a vet was called to sedate the animal.

"Despite the best attempts by officers and the vet the horse managed to get onto the M25, causing the road to be closed at Junction 30.

"For the safety of motorists and to prevent further suffering to the horse fire arms officers shot the animal."

There are now long delays and intermittent lane closures on the M25 anti-clockwise at the tunnel, with congestion stretching for miles.

The traffic, queued back on the London-bound stretch of the A2 past the central Gravesend junction, has now been exacerbated by a crash by the Gravesend West turn off.

The congestion, with heavy Friday traffic, has clogged up the entire road network in north west Kent.

The A225 though Sutton At Hone, the B260 through Darenth, the A226 through Stone and the A206 through Greenhithe are at a complete standstill.

There was is another accident west of the crossing at Bexley, for traffic going coast bound towards the Dartford Tunnel.

An incident on the anti-clockwise exit slip road at junction 30 for Thurrock is also adding to the backlog of traffic.

Emergency workers are stopping traffic at times to prevent queues inside the tunnels, with problems all morning from the Essex side at J30 and J31.

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