ALGIERS, Algeria — Algerian state news service says nearly 100 out of 132 foreign hostages have been freed from a gas plant that Islamic militants took deep in the Sahara.

Meanwhile the militants offered to trade two American hostages for terror figures jailed in the United States, according to a statement received by a Mauritanian news site.

The two are the mastermind of the 1993 World Trade Center bombing and a Pakistani scientist convicted of shooting at two U.S. soldiers in Afghanistan.

It was the latest surprising development in a hostage drama that began Wednesday when militants seized hundreds of workers from 10 nations at Algeria’s remote Ain Amenas natural gas plant.

Algerian forces retaliated Thursday by storming the plant in an attempted rescue operation that killed at least four hostages and left leaders around the world expressing strong concerns about the hostages’ safety.

Algerian special forces resumed negotiating today with the militants holed up in the refinery, according to the Algerian news service, which cited a security source.

Its report said “more than half of the 132 hostages” had been freed in the first two days, but it could not account for the remainder, saying some could be hidden throughout the sprawling desert site.