Seven hostages were executed today as Algeria’s four-day hostage stand-off came to a bloody end when the country’s special forces stormed the remote desert gas plant.

The army killed 11 militants during the ‘final assault’ on Al Qaeda-linked gunmen, but not before they in turn executed seven hostages, the state news agency reported

Defence Minister Philip Hammond confirmed the hostage crisis had ended with further deaths at a joint press conference with U.S. Defence Secretary Leon Panetta.

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‘It is the terrorists that bear the sole responsibility,’ he told reporters as called the loss of life ‘appalling and unacceptable.’

Mr Panetta said much remains ‘sketchy’ about what happened at the remote Ain Amenas gas field.

Today’s rescue mission was carried out in ‘extremely complex circumstances” against terrorists armed with a huge arsenal of missiles, rocket launchers, grenades and assault rifles, said an Algerian government source.

The exact death toll among the gunmen and the foreign and Algerian workers at the plant near the town of In Amenas close to the Libyan border remained unclear.

Earlier today, Algerian special forces found 15 burned bodies at the plant.

Efforts are now underway to identify the bodies and it was not clear how they had died.

Sixteen foreign hostages were freed at lunchtime including two Americans, two Germans and one Portuguese.

The attack on the plant swiftly turned into the biggest international hostage crises in decades, pushing Saharan militancy to the top of the global agenda.

Speaking after chairing a meeting of the government’s emergency committee, Cobra, William Hague did not mention the raid, but said the large majority of British nationals involved had been accounted for, but there were ‘fewer than 10’ who remained at risk or unaccounted for.

‘Therefore we must continue to prepare ourselves for bad news,’ he said

The British ambassador is to fly to an Algerian gas facility along with a small consular and political team to In Amenas, the town close to the plant to give consular support.

Prime Minister David Cameron had put SAS soldiers on standby in case the Algerian forces needed assistance.

The U.S. State Department said on yesterday one American, Frederick Buttaccio, had died but gave no further details.

Two Norwegians were released overnight, leaving six unaccounted for, while Romania said three of its nationals had been freed.

A number of Japanese engineering workers were still unaccounted for.

Scores of Westerners and hundreds of Algerian workers were inside the heavily fortified compound when it was seized before dawn on Wednesday by Islamist fighters who said they wanted a halt to a French military operation in neighbouring Mali.

The militants attacked the plant on Wednesday morning.

They crept across the border from Libya, 60 miles away, and fell on a pair of buses taking foreign workers to the airport.

The buses’ military escort drove off the attackers in a blaze of gunfire that sent bullets zinging over the heads of crouching workers.

A Briton and an Algerian – probably a security guard – were killed.

Frustrated, the militants turned to the vast gas complex, divided between the workers’ living quarters and the refinery itself, and seized hostages, the Algerian government said. The gas flowing to the site was cut off.

On Thursday, Algerian helicopters opened fire on a convoy carrying both kidnappers and their hostages, resulting in many deaths, according to witnesses.

Hundreds escaped on Thursday when the army launched its operation, but many hostages were killed.

In their final communications, the militants said they were holding seven hostages: three Belgian, two Americans, a Japanese and a Briton.

They had threatened to kill them if the Algerian army attacked.

Now a massive manhunt is underway to find Mokhtar Belmokhtar the deadly mastermind – dubbed the Marlboro Man – behind the hostage carnage in the Sahara desert.

A bounty on the one-eyed fanatic’s head – currently $100,000 – is expected to be put up to $1 million – around £700,000.

The militant militia leader had offered to trade two of the American hostages for two prominent terror figures jailed in the United States after 9/11.

Scene: The plant is located in In Amenas, around 60 miles from the Libyan border and 800 miles from the capital in Algeria’s vast desert south

David Cameron held talks with U.S. Defence Secretary Leon Panetta in Downing Street yesterday to coordinate an intelligence effort to locate Belmokhtar who is dubbed the Marlboro Man because he raises funds for terrorist atrocities by smuggling cigarettes.

Mr Panetta said that the terror gang ‘will have no place to hide’.

‘Terrorists should be on notice that they will find no sanctuary, no refuge, not in Algeria, not in North Africa, not anywhere,’ he said in a speech to security specialists in London.

Aged 19 he lost an eye mishandling explosives when training in an Al Qaed camps in war-torn Afghanistan, giving rise to another of his nicknames: One Eye.

Calling himself the leader of the Signed-in-Blood battalion, he was not at the gas facility himself.

But his jihadist henchmen mined huts where they were holding the hostages and then strapped explosives on to the terrified Westerners on his instructions.

Today a freed hostage described how Islamist militants shot dead a Briton after forcing him to tell colleagues to come out of hiding.

The man, only giving him name as Chabane, worked in the food service at the In Amenas plant and said he bolted out of a window and was hiding when heard the militants speaking among themselves with Libyan, Egyptian and Tunisian accents.

At one point, he said, they caught a Briton.

‘They threatened him until he called out in English to his friends, telling them, ‘Come out, come out. They’re not going to kill you. They’re looking for the Americans’.

A few minutes later, they blew him away,’ he said.

Many of the foreign workers hid throughout the drama – three Britons climbed into the ceiling of a canteen – to evade the terrorists as they searched for more captives.

Iain Strachan, 38, from Howwood in Renfrewshire, was among 100 foreign workers freed from the terrorists on Thursday.

Speaking on Algerian television, Mr Strachan said he was ‘very relieved to be out.’

‘Obviously we still don’t really know what’s happening back on site,” he said.

‘So, as much as we’re glad to be out, our thoughts are with colleagues who are still there at the moment.”

He said the Algerian army’s assistance has been ‘fantastic.’

Another hostage, Mark Grant, 29, from Grangemouth, reportedly texted his wife to let her know he was safe.

The message read: ‘I’m safe. Got me out this afternoon. With the Algerian army.’

One of the first Britons to be freed, Darren Matthews, 29, an electrical engineer from Teesside, said:

‘My heart goes out to the guys that are still there and hopefully everyone comes home safe because, at the end of the day, it’s only work.’

It is linked to Al Qaeda and made up of terrorists from a number of countries, including the Algerian, Mokhtar Belmokhtar.

Released captives have already spoken of one Islamist having a ‘perfect English accent’ – raising the possibility that some of the terrorists may have links with the UK.

Numerous expatriates including Britons work at the multi-million pounds facility, raising fears that somebody with inside knowledge may have helped organise the raid.

The first Briton to be killed in the crisis worked for a private security and safety firm, Stirling Group, which is based in Macclesfield, Cheshire.

The worker was not named but his family was informed.

He was killed when 32 terrorists from the al-Qaeda-linked Masked Brigade attacked buses ferrying workers to and from the local airport on Wednesday.

The terrorists originally said they wanted France to pull its troops out of neighbouring Mali, where a ground war is being fought against Al Qaeda.

The Masked Brigade had announced that are were willing to trade American hostages for two terrorists held in the US. , but a State Department spokesman said: ‘The United States does not negotiate with terrorists.”

On Friday, Britain’s ambassador to the United Nations said that he would be proposing a statement from the UN Security Council condemning the attack.

‘That could happen in the next few hours, it could happen over the weekend,’ Sir Mark Lyall Grant said in a press conference in New York. “Obviously it depends on the fluid situation on the ground’.

Video: Algerian State TV speak with men who were held hostage

– Daily Mail UK