IN AMENAS, Algeria: Islamist gunmen were holed up with an unknown number of foreign hostages on Saturday at a remote gas plant in the Algerian desert, as the world awaited the military's next move to free them.

More than 72 hours after the heavily armed militants staged a deadly raid on the complex, and two days after Algerian special forces launched a botched rescue bid widely condemned as hasty, there appeared to be a stand-off in the Sahara.

"There's no change since yesterday; the situation remains the same," an Algerian security official told AFP as army helicopters overflew the In Amenas gas plant near the border with Libya.

On Friday, a security official said troops were trying to reach a "peaceful" end to the crisis, before "neutralising the terrorist group that is holed up in the plant and freeing a group of hostages still being held there."

Amid a virtual news blackout in Algiers, harshly criticised by local media, world leaders took a tough stand on the fate of the remaining hostages.

US Defence Secretary Leon Panetta said Washington would "take all necessary steps to protect our people" from the threat of Al-Qaeda-affiliated militants in north Africa.

"Whether or not that involves assisting others with military operations, whether it involves developing in a cooperative way operations there, those are areas that I think remain to be decided," he told the BBC.

Earlier, US Secretary of State Hillary Clinton told a news conference with Japanese Foreign Minister Fumio Kishida of her deep concern "about those who remain in danger. Utmost care must be taken to preserve innocent life."

At least one American has been confirmed dead.

In Tokyo, Prime Minister Shinzo Abe ordered his government to do everything possible to ensure the safety of those Japanese unaccounted for in "an extremely despicable" incident that "can never be forgiven."

"I would like you to do your best to confirm the safety of the Japanese and rescue them by using every possible means," Abe told top officials after cutting short a trip to Southeast Asia.

An Algerian security official put the number of foreign hostages at 10, but more workers remain unaccounted for, including at least 10 Japanese and eight Norwegians.

Norway's Statoil, which jointly operates the site with Britain's BP and Sonatrach of Algeria, said two Norwegians have been found alive but six others remain unaccounted for.

The gunmen, cited by Mauritania's ANI news agency, said on Saturday they were still holding "seven foreign hostages," denying claims of more.

On Friday, they gave a breakdown of three Belgians, two Americans, one Japanese and a Briton, although Belgium said there was no indication any of its nationals were being held.

The fate of two Malaysians believed caught up in the crisis remains unknown, Kuala Lumpur said, while Romania said three of its citizens had been freed.

France, which the Islamists have demanded end its military intervention in neighbouring Mali, said on Saturday that no more of its citizens were being held.

Algerian news agency APS quoted a government official as saying the kidnappers, who claimed to have come from Niger, were armed with machineguns, assault rifles, rocket launchers and missiles.

This was confirmed by an Algerian driver, Iba El Haza, who added that the hostage-takers spoke in different Arabic dialects and perhaps also in English.

"From their accents I understood one was Egyptian, one Tunisian, another Algerian and one was speaking English or (another) foreign language," Haza told AFP, two days after escaping during the army's Thursday assault.

"The terrorists said: 'You have nothing to do with this, you are Algerians and Muslims. We won't keep you, we only want the foreigners.'"

Algeria's El Watan daily quoted a former military officer as justifying the army's assault, saying: "All hesitation is forbidden when the future of the nation is at stake or being threatened."

The gunmen belong to a group known as "Signatories in Blood," led by Algerian Mokhtar Belmokhtar, a former senior Al-Qaeda commander in north Africa.

The group is demanding an end to French intervention against Islamists in neighbouring Mali, ANI quoted sources close to Belmokhtar as saying.

Belmokhtar also called for exchanging American hostages for the blind Egyptian sheikh Omar Abdul Rahman and Pakistani Aafia Siddiqui, jailed in the United States on charges of terrorist links.

But State Department spokeswoman Victoria Nuland said "the United States does not negotiate with terrorists."

Meanwhile, France said on Saturday that 2,000 of the 2,500 troops it had pledged were now on the ground in Mali.

Foreign Minister Laurent Fabius said at a meeting in Abidjan that "France was obliged to intervene very, very rapidly, otherwise there would have been no more Mali. But it is well understood that it is the Africans that must pick up the baton."