In this image made from video, a group of people believed to be hostages kneel in the sand with their hands in the air at an unknown location in Algeria.

Algiers, Algeria -

Two Britons both made extraordinary escapes from terrorists holding them hostage in the Algerian BP gas plant by trekking across the desert for 20 hours.

Exhausted and dehydrated, they walked lost for almost 25km, hiding behind sand dunes while all the time fearing they would walk into the hands of al-Qaeda’s fighters before eventually making it to safety.

Details emerged on Sunday as a third Briton, Alan Wright, 37, told how he had been part of what he called “the Great Escape” by another group of 30 hostages, who had cut through the wire mesh of the plant’s fence - only to run into a heavily armed checkpoint.

Wright and his companions feared it was manned by fighters from the “Blood Battalion” responsible for the murders of their colleagues after seizing the remote compound near In Amenas in the Sahara desert before dawn on Wednesday.

Wright, separated at gunpoint into a group of four international hostages and made to kneel in the sand with hands on his head, thought he had made the “biggest mistake” of his life.

“That was a horrible, horrible thing ... you have escaped then walked into the hands of the terrorists, or so we thought... You just think that’s it... you fear the worst, you can’t put into words how bad you feel,” he said on Sunday.

But after an agonising 20 minutes the armed men at the checkpoint revealed themselves to be Algerian soldiers.

Three Britons are so far confirmed to have died during the siege in the Sahara with fears for three more missing, believed dead. In all, 22 survived. Their stories emerged as:

* Jihadist mastermind Mokhtar Belmokhtar claimed responsibility in the name of al-Qaeda for the mass hostage-taking and called on France to halt air strikes in neighbouring Mali.

* The combined death toll of hostages and attackers rose to 81, and was expected to increase further.

* Five terrorists were captured alive - some are said to have been working on short-term contracts at the gas facility, raising the possibility the foreign workers knew their killers.

* An Algerian government statement said 107 foreign hostages and 685 Algerian hostages had survived.

* Algerian authorities put a huge arsenal of terrorist weapons on display.

British Prime Minister David Cameron said the “cowardly attack” was a “stark reminder” of the continuing terrorist threat. But he was careful not to criticise the Algerians, whose bomb squads were defusing mines and booby traps at the gas plant on Sunday while searching for bodies.

All the British survivors are being questioned by Special Branch and intelligence officers about their ordeal.

Among them was 56-year-old father of two Lou Fear, a team leader for BP, whose escape was among the most dramatic.

He trekked for 20 hours during the baking temperatures of the day and freezing night to reach safety.

With little food and water, Fear could hear gunfire and explosions from the gas plant and all the time feared he would be found - and killed - by the terrorists.

When the raid on the refinery began, Fear had tried to help the wounded before he and a handful of colleagues hid while terrorists searched for them.

At one stage, said a witness, the attackers forced a Briton to shout out: “Come out, come out, they’re not going to kill you. They’re looking for the Americans.” But, said the witness: “A few minutes later, they blew him away.”

Fearing it was only a matter of time before their hideout was found, Fear decided to make a break for it through holes cut in the fencing. When not walking, the men hid in dunes and what little cover the barren desert landscape afford.

It is thought he and his colleagues were trying to reach the nearest town, In Amenas, 15 miles from the gas plant, but were rescued after walking into an Algerian army patrol.

Fear, who lives in Louth, Lincolnshire, is now back in Britain, where he has been reunited with his wife Lori and their children, Anna-Victoria, 21, and Richard, 23.

Mrs Fear, an elder at a Baptist church, said: “I’m just relieved to have my husband back .He’s very traumatised.”

Fear, who in 2004 had helped to build the gas plant, said: “The guys who picked us up were wonderful, they were like long lost friends. They kept saying, ‘The terrorists did not come from Algeria’.”

A second, unnamed, Briton was among other small groups which also managed to escape in a similar fashion.

Their ordeals as they made their way through the desert mirrored that of Wright, a father of two from Portsoy in Aberdeenshire.

He said he hid in an office before joining Algerian colleagues in cutting their way through a fence and fleeing.

“If you have been captured, there’s pretty much no escape and it is going to take a miracle to get you out,” he said on Sunday.

The terrorists had tried to clear all the buildings of workers and one of the jihadists patrolled the area outside their hideaway and tried to trick them out.

Wright said a man walked past saying good morning in a very friendly Arabic voice. “That was the first moment when we thought we are in big trouble here,” he said.

The group then spent a terrifying nine hours trying to stay out of sight and wondering what was happening, covering the windows with newspaper. The next day Wright was given a hat to wear to make him ‘look less expat’ and the group, which had now swollen to about 30, made a break for it.

They cut the perimeter fence but were still worried because the terrorists were dressed the same as the Algerian security forces, so they had no real way of knowing who to trust.

Wright added: “With the first cut of the fence, the wire made such a noise when it broke and we knew it travelled to where the terrorists were ... but within 30 seconds both fences had been cut open and we were free to go, that was it.”

Speaking after being reunited with his 31-year-old wife Karlyn, Wright said it was important not to run and attract attention to themselves.

“You know these guys are behind you and if they see you, you don’t know if they’re going to be shooting at you, you just don’t know where everybody is...

“There was a mixture of relief, but you’ve no idea of what is out there. We got about a kilometre into the desert and could see the military checkpoint with eight or nine personnel with guns pointing into our spot, but also that they had identified us and were making tracks to come our way.

“Then you think, ‘Is it the terrorists or is it the gendarmes?’ And for 20 minutes you’re still not sure - we’re down on your knees with our hands up.”

The group was then split into Algerians and expatriates and Wright thought they had walked into the hands of the terrorists before it eventually became clear that they were with the country’s soldiers.

“You fear the worst, you can’t put into words how bad you feel,” he said. “It’s something you never want to go through again.”

Algerian special forces stormed the facility on Saturday to end the four-day siege and later recovered a terrorist arsenal of six machine guns, 21 rifles, two shotguns, two 60mm mortars with shells, six 60mm missiles with launchers, two rocket-propelled grenades with eight rockets and ten grenades in explosive belts.

The militants came from six countries, were armed to cause maximum destruction, and had mined the In Amenas refinery, which the Algerian state oil company runs along with BP and Norway’s Statoil.

Foreign Secretary William Hague branded the militants “cold-blooded murderers” and said reports they had “executed” seven of their hostages before the final battle could well be true.

Last BP said four of its employees from the joint venture gas plant were still missing. In a statement, the company said: “At the time of the attack there were 18 BP employees at In Amenas; 14 of them are safe and secure. Two of the 14 have sustained injuries, but these are not life-threatening.

“BP remains gravely concerned about four of its employees who are missing. There is no further confirmed information regarding their status at this time.”