The Islamic State freed 43 Assyrian Christian hostages in northeastern Syria on Monday, human rights groups have confirmed.
The captives are the last of over 200 Christians to be released after their kidnapping last February from villages near Tal Tamr.
According to Newsweek, the terrorist group freed the captives after receiving ransoms of $100,000 per person. While the ransoms were agreed upon in the IS stronghold of Raqqa, it remains unclear where the hostage exchange took place.
Younan Talia of the Assyrian Democratic Organization told The Associated Press that the terrorist group had originally demanded $18 million for the hostages' release, but that figure was lowered after months of negotiation.
Several Christian aid groups collaborated with IS-affiliated Sunni tribal leaders to facilitate the trade, Newsweek reported.
The Assyrian Church of the East Relief Organization, which played a role in negotiating the hostage release, said in a statement on its Facebook page that while it celebrates the recent victory, it mourns the lives of other Assyrians lost to the Islamic State.
"ACERO wishes to extend its unreserved thanks to all those supporters, both institutional and individual, who have stood with the Assyrians of Syria in this arduous 12-month period," the aid group said.
"While this news thankfully marks the end of the most recent tribulation, we mourn the tremendous losses, both human and material, suffered by the indigenous Assyrians of Syria. The destruction of their livelihoods in the historic Khabur villages is a loss for the Assyrian nation and for Syria as a whole," the organization stated.
An anonymous Syrian Christian activist told the AP that the Assyrian Church was able to secure the money for the exchange after receiving donations from around the world.
"We paid large amounts of money, millions of dollars, but not $18 million," the activist, who participated in the negotiations, told the media outlet, adding, "We paid less than half the amount."
The Syrian Observatory for Human Rights confirmed last February that over 200 Christian men, women and children had been kidnapped from the villages surrounding Tal Tamr.
The terrorist group had reportedly rounded up hostages by traveling along the south bank of the Khabur river before dawn, the BBC reported.
Following the kidnappings, the U.S. State Department issued a statement condemning the attack as "brutal and inhumane treatment."
"ISIL's latest targeting of a religious minority is only further testament to its brutal and inhumane treatment of all those who disagree with its divisive goals and toxic beliefs," the department said last February.
The White House released a similar statement saying the kidnappings were proof of the terrorist group's "depravity."
"The international community stands united and undeterred in its resolve to bring an end to ISIL's depravity. The United States will continue to lead the fight to degrade and ultimately defeat ISIL."
The terrorist group freed the hostages in stages, releasing 16 in January, 25 in December 2015, 10 in November 2015 and 19 in March 2015.