Firefighters saved homes, Royal woodlands and a nature reserve, as flames engulfed several acres of Norfolk heathland.

Crews were still damping down at the scene of the fire at Dersingham Heath, on the edge of the Royal Estate, until past midnight.

Flames tore across the tinder-dry heath after undergrowth caught light yesterday afternoon. The cause of the fire remains unknown.

A crowd gathered to watch on the hill by the village sign, as firefighters from across Norfolk spread out across the heath with hoses and hand extinguishers.

They were forced to retreat as the fire quickly spread. Fanned by the breeze, the flames reached gorse and trees alongside the busy A149.

Police closed the road between the Ken Hill and Alderman Pratt roundabouts for more than four hours, as the road became enveloped by smoke.

Long tailbacks built up as drivers heading to and from the coast were diverted via Dersingham and Ingoldisthorpe, on what the AA predicted would be one of the busiest days of the year on Norfolk's roads.

'You couldn't think of a worse day for something like this to happen,' said one police officer. Asked by a driver how far back the queues stretched, he shrugged: 'Wisbech.'

By 4pm, there were 10 appliances and a bulk water tanker at the scene.

Efforts to fight the flames were hampered by boggy ground, which meant fire engines could not get close to the seat of the fire.

'Since it started, the wind's got up,' said station manager John Burrows, from Fakenham, as he led the operation.

'We'll be here damping it down for a considerable period.

The main road became the front line, as full-time and retained crews lined their fire appliances up and attacked the flames head-on.

As our dramatic pictures show, both appliances and firefighters were engulfed in smoke, as drivers stuck on the roundabout watched the drama unfold a few hundred yards up the bypass.

Others surrounded a cottage close to the Alderman Pratt roundabout, as the fire came within 20 yards of its garden, using hoses to save the property.

A pine tree burst dramatically into flames, showing what lay in store if the fire reached the pine woods on the Sandringham Estate.

Equally flammable silver birch trees lay in its path – as well as Dersingham Bog, a 300-acre national nature reserve famed for its rare plants and insects.

But the firefighters' efforts paid off, as crews pumped thousands of gallons of water at the blaze. First, the smoke began to thin - revealing fire engines and firefighters at work. By 5pm, the flames were retreating.

Onlookers said the fire was the second on the heath in as many days, with a smaller fire being started deliberately by youths on Thursday.

Villager Anthony Taylor said: 'A couple of youngsters started it and ran away. I walked through there last week, it's so dry.'

Neighbour Hannah Griffiths – a presenter with King's Lynn-based radio station KLFM 96.7 – said: 'It's been so dry it's not a surprise, we've had one of the driest Aprils ever.'