Islamic militants have reportedly offered to trade two American hostages for terror figures jailed in the United States, as a violent siege continues at a gas plant in Algeria. A Mauritanian news site that often reports news from North African extremists received a statement about the offer Friday.

Some 60 foreign hostages are still unaccounted for three days into the raid, Algeria’s state news service said Friday.

The militants — led by a Mali-based Al Qaeda offshoot known as the Masked Brigade — suffered losses in Thursday’s military assault, but succeeded in garnering a global audience.

Algerian forces who had ringed the Ain Amenas complex in a tense standoff had vowed not to negotiate with the kidnappers, who reportedly were seeking safe passage. Security experts said the end of the two-day standoff was in keeping with the North African country’s tough approach to terrorism.

The kidnapping is one of the largest ever attempted by a militant group in North Africa. The militants phoned a Mauritanian news outlet to demand that France end its intervention in neighboring Mali to ensure the safety of the hostages in the isolated plant, located 800 miles south of the capital of Algiers.

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