The United States Commission on International Religious Freedom released a statement on Tuesday condemning the execution of five aid workers kidnapped by an Islamic extremist group.

The aid workers were kidnapped last month and their killing was publicly announced last week by members of the Islamic State in West Africa Province (ISWAP). The ISWAP is a breakaway faction of Boko Haram, another Islamic extremist terrorist group.

“ISWAP’s execution of aid workers is beyond reprehensible. The militant Islamic group shows no remorse as it continues to target civilians based on their faith,” said USCIRF Vice Chair Tony Perkins in a statement July 28.

On July 23, the ISWAP claimed to have killed the five aid workers in its weekly digital newsletter. The workers were kidnapped in separate incidents during the first two weeks of June.

The ISWAP posted a video of the execution on YouTube on July 22, where it was quickly removed. In the video, one of the militants states that the executions were in retaliation for efforts to purportedly convert Muslims to Christianity.

“This is a message to all those being used by infidels to convert Muslims to Christianity,” one of the executioners said in the video, which was translated by Morning Star News. Morning Star News is a news organization that highlights persecution of Christians.

“We want you out there to understand that those of you being used to convert Muslims to Christianity are only being used for selfish purposes,” said the militant, adding that Christian organizations did not care about the welfare of the kidnapped workers.

“We therefore call on you to return to Allah by becoming Muslims. We shall continue to block all routes [highways] you travel,” said the militant. “If you don’t heed our warning, the fate of these five individuals will be your fate.”

According to Morning Star News, three of the five men executed in the video were known employees of Christian aid agencies. Mohammad Buhari, the president of Nigeria, said the other two men were employed by secular aid agencies.

Buhari, through a spokesman, expressed condolences to the families of those slain and promised to see that “every remaining vestige of Boko Haram is wiped out completely from northeastern Nigeria.”

“President Buhari also condoles with the State Emergency Management Agency, Action Against Hunger, Rich International, and International Rescue Committee, whose staff have suffered this gruesome fate,” said the statement. “He thanks them for their continued dedication and service to the victims of Boko Haram in Northeastern Nigeria.”

More than 600 Christians have been killed so far in 2020, according to a report on May 15 by the International Society for Civil Liberties and the Rule of Law (Intersociety). Christians have been beheaded and set on fire, farms set ablaze, and priests and seminarians have been targeted for kidnapping and ransom.

The crisis of violence facing Christians in Nigeria has attracted increasing international scrutiny and condemnation.

Speaking on a panel organized by In Defense of Christians last month, Bishop Matthew H. Kukah of the Nigerian Diocese of Sokoto said that the situation in the country stems from a culture that has devalued Christianity and no longer cares about faith.

“This is the vacuum that [extremists] are exploiting--mainly, a west that is in retreat, as far as Christianity and Christian values are concerned, a west in which diplomats and businesspeople are far from being interested in matters of faith, especially when it comes to Christianity,” said Kukah.

On July 8, a report, published by Competere, a trade law and economic policy consultancy, highlighted the persecution of Christians in Nigeria’s Middle Belt states and urged the U.K. government to use new powers to penalize individuals who are complicit in the violence.

In February, Ambassador Sam Brownback, the U.S. ambassador-at-large for international religious freedom, told CNA that he was particularly concerned about Christian persecution in Nigeria. Particularly, Brownback was concerned that violence originating in Nigeria could spread throughout the region, and that the Nigerian government was not doing enough to protect its people from extremists.

“I think we’ve got to prod the [Nigerian President Muhammadu] Buhari government more. They can do more,” Brownback said to CNA. “They’re not bringing these people to justice that are killing religious adherents. They don’t seem to have the sense of urgency to act.”