World

In a bloody finale, Algerian special forces stormed a natural gas complex in the Sahara desert on Saturday to end a standoff with Islamist extremists that left at least 19 hostages and 29 militants dead. Dozens of foreign workers remain unaccounted for, leading to fears the death toll could rise.

With few details emerging from the remote site in eastern Algeria, it was unclear whether anyone was rescued in the final operation.

The siege at Ain Amenas transfixed the world after radical Islamists linked to al-Qaida stormed the complex, which contained hundreds of plant workers from all over the world, and then held them hostage surrounded by the Algerian military and its attack helicopters for four tense days that were punctuated with gunbattles and dramatic tales of escape.

There were reports Friday that a news agency in Mauritania, Agence Nouakchott Information, has quoted an unnamed source with the militant group who says the hostage-takers included people from Mali, Egypt, Niger, Mauritania and Canada.

Ottawa said Friday it is "pursuing all appropriate channels to seek further information" and is in close contact with Algerian authorities.

Meanwhile, a Canadian who was among the employees at the facility when the attack was launched on Wednesday is safe.

Algeria's response to the crisis was typical of the country's history in confronting terrorists, favoring military action over negotiation, which caused an international outcry from countries worried about their citizens. Algerian military forces twice assaulted the two areas where the hostages were being held with minimal apparent mediation, first on Thursday and then on Saturday.

In the final assault, the remaining band of militants killed seven hostages before special forces killed 11 of the attackers, the state news agency said. It wasn't immediately possible to verify who killed the hostages. The military launched its assault to prevent a fire started by the extremists from engulfing the complex, the report said.

The seven hostages and 11 militants adds to the previous toll of 12 captives and 18 kidnappers, according to the government, but there are fears that the number of hostages killed is much higher and dozens of foreign workers from the Ain Amenas site remain unaccounted for.

The site of the gas plant spreads out over several hectares (acres) and includes a housing complex and the processing site, about a mile apart, making it especially complicated for the Algerians to secure the site and likely contributed to the lengthy standoff.

"It's a big and complex site. It's a huge place with a lot of people there and a lot of hiding places for hostages and terrorists," said Col. Richard Kemp, a retired commander of British forces who had dealt with hostage rescues in Iraq and Afghanistan. "These are experienced terrorists holding the hostages."

Casualty figures varied widely. While the Algerian government has only admitted to 19 hostages dead so far, the militants claimed through the Mauritanian news website ANI that the helicopter attack alone killed 35 hostages.

The attack by the Mali-based Masked Brigade, founded by Algerian militant Moktar Belmoktar, had been in the works for two months, a member of the brigade told the ANI news outlet. He said militants targeted Algeria because they expected the country to support the international effort to root out extremists in neighbouring Mali and it was carried out by a special commando unit, "Those Who Signed in Blood," tasked with attacking nations supporting intervention in Mali.

The kidnappers focused on the foreign workers, largely leaving alone the hundreds of Algerian workers who were briefly held hostage before being released or escaping.