AIN AMENAS, Algeria — The Algeria state news agency said this morning that the Algerian Army has launched a final assault against Islamist extremists at a sprawling gas plant in the middle of the Sahara desert

Apparently, 7 hostages, 11 kidnappers have been killed

The four-day standoff has put the spotlight on militancy plaguing the region and al-Qaida-linked groups roaming remote areas from Mali to Libya, threatening vital infrastructure and energy interests.

Algerian authorities have given no clear sign of how many people are still alive or captive at the Ain Amenas plant in southeast Algeria as of this morning. The plant is jointly run by BP, Norway’s Statoil and Algeria’s state-owned oil company.

On Friday, it became clear the Algerian forces had retaken only the living quarters. The hostages and their kidnappers remained ensconced in the refinery.

The site of the gas plant spreads out over several hectares (acres), with dozens of buildings, making it especially complicated for the Algerians to secure the site and even find where the hostages are being held.