The UN Security Council on Friday strongly condemned the "heinous" attack and hostage-taking at an Algerian gas complex by Al-Qaeda linked militants.

A statement agreed by the 15-member council stressed the need to bring the Al-Qaeda linked attackers and their backers to justice.

At least 12 hostages and 18 kidnappers were killed in an assault by Algerian security forces on the Sahara desert complex. Between seven and 10 hostages were still being held.

"The Security Council condemned in the strongest terms the terrorist attack in In Amenas, Algeria," said the statement.

The council expressed "deep sympathy and sincere condolences to the victims of these heinous acts and their families and to the people and governments of Algeria and those countries whose nationals have been affected."

It "underlined the need to bring perpetrators, organisers, financiers and sponsors of these reprehensible acts of terrorism to justice."

In addition, it urged all countries "to cooperate actively with the Algerian authorities" in line with international law and Security Council resolutions.

The statement also added a phrase that said countries must ensure that "measures taken to combat terrorism comply with all their obligations under international law, in particular international human rights, refugee and humanitarian law."

Several countries have urged Algeria to do everything to prevent harm to the remaining hostages at In Amenas.