They come galloping out of the volcanic storm, hooves muffled in the ash, manes flying.

Shutting the last of his 17 horses into an old barn, Ingi Sveinbjoernsson, 56, breathes a sigh of relief.

Only 24 hours earlier he had lost the shaggy Icelandic horses in an ash cloud that turned day into terrifying night, blanketing the wild landscape in glutinous grey mud.

"I went out to fetch them and realised I couldn't see my own hand. That's how dark it was," he said, shaken. "I never imagined anything like it."

The Icelandic horse is something of a national emblem on the north Atlantic island.

About 80,000 live in Iceland, according to the Horse Breeding Association - a horse for every four people in a population of almost 320,000.

Pony-like in size, but immensely sturdy, and crowned with tufty forelocks and thick manes, Icelandic horses are also valuable, a top stallion fetching hundreds of thousands of dollars.

So when Eyjafjoell volcano erupted last week, spewing dust across Europe and debris over southern Iceland, farmers raced their herds to cover.

Four-by-fours pulling horse boxes became a ubiquitous sight on roads leading away from the volcano.

Others were too late. They evacuated their horses only Saturday, when the ash storm was upon them, driving herds sometimes a hundred strong through blizzards of dust.

Still others, like Sigurgeir Ingolfsson, had to wait until a lull Sunday.

Ingolfsson said he made the "incredibly hard decision" to abandon his farm the previous day when the air became hard to breathe.

When he brought the horses in early Sunday they were matted with dust. "You could sense they were happy to come inside," he said.

At Yzta-Baeli farm, within sound of Atlantic waves and in direct line of Eyjafjoell volcano, Mr Sveinbjoernsson and two friends trudged through ash to gather their lost herd.

The spirited little horses pranced and tossed their heads, before cantering toward a corral. From there they were transferred, two by two, into a trailer, then the barn.

The horses' chestnut and honey-coloured hair disguised the ash that had rained on them. The herd's one white horse was streaked in grey and a slap on the rump of any of the beasts sent up puffs of volcanic dust.

Mr Sveinbjoernsson's family friend Ingimundur Vilhjalsson, 65, examined the horses.

A few appeared to have runny eyes, but Mr Vilhjalsson said the extent of ill effects was unclear.

"I think they're OK, but I don't know what they've been eating all that time, so I'm worried," he said.

The extraordinarily resilient animals - exported mostly to Europe for riding and as far as Japan for meat - almost never go indoors.

Postcards and tourist posters portray them as cute, almost vain-looking animals.

But they are as tough as Icelanders themselves, with double coats adapted to resist the fierce north Atlantic weather, five walking gaits, and easy going temperaments to boot.

"What makes the Icelandic pony so unique is its good temper and sure-footedness," Sveinn Steinarsson, south Iceland representative of The Horse Breeding Association, said.

He said the tainted grass is not immediately poisonous, but as fluoride levels rise from the ash, so does the danger.

"In areas where there's ash fall and horses are outside the conditions are terrible. They can't survive in this if it carries on too long. The horses have to be fed with hay and have access to running water to avoid them consuming a lot of ash."

Mr Vilhjalsson said he thought Iceland's volcano horses would survive.

"Because they're so small, their strength constantly surprises people," he said.

What he couldn't tell was how long these brave animals, usually scornful of home comforts, would be cooped up in the barn.

"I don't know," Mr Vilhjalsson said. "The volcano will decide."

- AFP