The ISIS terror group kidnapped 88 Eritrean Christians from a people-smugglers' caravan in Libya last week, a U.S. defense official confirmed Monday. 

The defense official confirmed initial reports of the mass kidnapping to Fox News after seeing a recent intelligence report. The independent Libya Herald newspaper reported that the convoy was ambushed by militants south of Tripoli before dawn this past Wednesday morning.

Meron Estafanos, the co-founder of the Stockholm-based International Commission on Eritrean Refugees, told the paper that the group of migrants included "about 12 Eritrean Muslims and some Egyptians. They put them in another truck and they put 12 Eritrean women Christians in a smaller pick-up".

Estafanos said that the militants had initially stopped the truck and demanded that the Muslims on board make themselves known. Everyone who responded was asked about the Koran and their religious observance in an attempt to catch Christians pretending to be Muslims. 

The main body of the group was put back on the original truck. As the militants drove the vehicle away, Britain's Daily Telegraph reported that at least nine men attempted to escape by diving off the back of the truck. Estefanos said three of those who had escaped were safe, but still trying to get out of Libya. The fate of the others was not known.

Libya has become a jumping-off point for thousands of migrants from the Middle East and sub-Saharan Africa who attempt the dangerous Mediterranean crossing to southern Europe. However, Libya's ongoing instability has led to an increased presence by ISIS and other terror groups, increasing the risk for Christians and other non-Muslims attempting the crossing.

In February, Libyan militants proclaiming loyalty to ISIS released a video showing the beheading of 21 Egyptian Coptic Christians at the edge of the Mediterranean Sea. Two months later, another video showed the militants shooting and beheading an indeterminate number of Ethiopian Christians. Estefanos told the Libya Herald that the video released in April had been edited and that 64 people had been massacred, including several Eritreans. 

"Ever since the kidnapping by ISIS in Libya last February," she said,  "many are taking different routes. Some go from Khartoum [Sudan] to Turkey, then Greece. Others are now leaving via Khartoum to Cairo, then Alexandria and from there by boat to Italy. I think we will see an increase towards Turkey and Cairo instead of Libya".

ISIS on Tuesday also claimed that it seized a power plant near the Libyan city of Sirte, which supplies central and western parts of the country with electricity, Reuters reports.

"The plant ... was taken," ISIS said in a message on social media, while forces loyal to the self-declared government that controls Libya's capital, Tripoli, fled the area, a military source told Reuters. The source said three soldiers were killed in the attack.

Libya is divided between rival governments and hundreds of militias in the aftermath of its 2011 civil war that ousted dictator Muammar Qaddafi. 

The violence has impacted the country's oil revenues heavily. U.N. envoy to Libya Bernardino Leon has warned that the country only has enough money to pay salaries for another six weeks, urging warring parties to agree on a unity government. Negotiators are currently meeting in Morocco to discuss a power-sharing agreement.

Fox News' Lucas Tomlinson and the Associated Press contributed to this report. 

Click for more from the Libya Herald.

Click for more from the Daily Telegraph.