The 'final assault' by Algerian troops on a gas plant seized by militants has resulted in the deaths of seven hostages and 11 kidnappers. The militants reportedly summarily executed their captives as troops tried to free them.

"It is over now, the assault is over, and the military are inside the plant clearing it of mines," Reuters quoted a local source as saying.

Earlier, the militants reportedly made demands and threatened to kill the captives if their ultimatum was not met.

The militant group behind the attack, ‘The Battalion of Blood,’ initially said that the hostages were nationals of Great Britain, Japan, the US and Norway, Mauritanian news agency Akhbar reported citing the militants' commander. 

The identity of the hostages killed has not been revealed.

The leader also said that his team of 20 militants had mined the facility where the hostages are being held, and threatened to blow it up if another rescue is attempted.

With the rescue operation ended, the Algerian army has reportedly begun clearing the facility.

Algerian Special Forces found 15 burned bodies at the gas plant on Saturday, the likely victims of a retaliation for an operation to free dozens of foreign and Algerian workers, Reuters said, citing a source familiar with the situation. An investigation is underway to identify the bodies. The circumstances of their death also remain unclear.

Malian militants seized the In Amenas natural gas installation in the Algerian Sahara on Wednesday, taking hundreds of hostages, including scores of foreigners. The militant group said it conducted the raid in retaliation for France’s engagement in the Mali crisis.

The militants also demanded the release of two terrorists held in the US in return for the hostages. One of the terrorists, Omar Abdel-Rahman, known as ‘The Blind Sheikh,’ played a role in the planning of the 9/11 attacks in 1993.

On Saturday, details emerged on the identity of the commanders of the militant group that had been holding the hostages since Wednesday. One of the group's leaders, a veteran fighter from Niger called Abdul Rahman al-Nigeri, headed a group of militants who were killed during the final assault. The other group's leader, Abu al-Bara'a al-Jaza'iri, was reportedly killed earlier by the Algerian army at the gas field's residential complex. Reports also suggested that the head commander of the kidnappers, Mokhtar Belmokhtar, who is linked to a regional Al-Qaeda group, was not at the plant during the militants’ assault.

An image grab taken from footage broadcast by Algeria's Al-Jazairia 3 TV on January 18, 2013 shows Algerian hostages after they fled their Islamist captors following a deadly commando raid by Algerian forces at a desert gas field in In Amenas. (AFP Photo / Al-Jazairia)

There were conflicting reports of foreign and Algerian hostage casualties during the government army’s three-day rescue operation. On Friday, state media said that at least 12 hostages were killed during the rescue operation. However, it was reported earlier that 30 hostages have died.

Algerian news outlet APS said that nearly 650 hostages have been freed, including 573 Algerians and 100 of the 132 foreigners being held.

On Saturday, 16 foreign hostages, including two Americans, two Germans and one Portuguese national, were reportedly freed in Algeria, Reuters said, citing to a local source. However, details on when or where the hostages were freed remain unknown.

Militants are believed to still be in control of the gas plant, while the residential premises housing hundreds of workers were recaptured by government forces in the rescue operation, Norwegian Prime Minister Jens Stoltenberg said.

A massive fire was witnessed at the huge plant late Friday, where many of the missing hostages are still believed to be held, Al Arabiya reported.

At least one US national was killed in the standoff, but it is unclear how he died. The body recovered Friday was identified as Frederick Buttaccio of Texas, the US State Department confirmed.

The hostages remain vulnerable at the facility, US Secretary of State Hillary Clinton acknowledged, without confirming any American deaths or announcing a death toll. “I want to underscore again that the utmost care must be taken to preserve innocent life,” she said, adding that Washington is in close contact with Algerian officials.

As far as Paris is aware, there are no more French hostages being held in the Algerian gas complex, French Defense Minister Jean-Yves Le Drian stated on Saturday.

French foreign minister Laurent Fabius meanwhile acknowledged that one French hostage was killed during the rescue attempt, while three others were saved.

And Norwegian firm Statoil revealed Saturday that two more of its workers had been freed and moved to safety, leaving six unaccounted for. There are no details as to how the two managed to escape.

A number of countries, including the UK and Japan, have expressed their dissatisfaction over how the hostage situation has been handled. They take issue with the fact the rescue operation was ordered without consultation and resulted in hostage casualties.

The UK government’s emergency committee COBRA will hold a meeting on the hostage crisis on Saturday chaired by Foreign Secretary William Hague. The hostages will "remain top priority until every British national [is] accounted for," Hague wrote on Twitter prior to the meeting.

There are “fewer than 10” UK citizens remaining “at risk” and the “large majority” are now "safe and accounted for,"Foreign Secretary Hague said in the interview shortly after news broke that the raid had ended.

The US State Department issued a travel warning on Friday advising Americans against traveling to the west African country. US officials are concerned of possible further attacks and kidnappings by the militants. There is also a possibility of food shortages in the war-ravaged country.

This photo released by EADS' Astrium Press on January 18, 2013, shows a satellite view of the In Amenas gas field in the Sahara desert. (AFP Photo / EADS)

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