A Reuters report has confirmed that Shiite militias closely aligned with the Iranian government and the terror group Hezbollah are actively participating in the liberation of Mosul, Iraq, from the Islamic State, following repeated denials from the Pentagon.

The Shiite Popular Mobilization Forces (PMF) have begun moving closer to Mosul, the capital of the Islamic State in Iraq and the nation’s second-largest city. The Islamic State captured the city in 2014, and the government of Iraqi Prime Minister Haider al-Abadi announced an operation to liberate the city earlier this month. The Iraqi army has agreed to cooperate with Kurdish Peshmerga forces and the U.S. government in the endeavor.

It also has, Reuters notes, incorporated the PMF into the operation. The group has begun operating while “flying the banners of Shi’ite militias along with Iraqi flags while blaring religious songs.”

Shiite religious fight songs, or nasheeds, are distinguishable from their Sunni counterparts by their use of percussion, which is haram for Sunni jihadists. All Islamic State nasheeds are a capella.

The PMF, Reuters adds, are “mostly made up of groups trained by Iran and loyal to its Supreme Leader, Ayatollah Ali Khamenei,” and have repeatedly been linked to the world’s largest Shiite terrorist group, Hezbollah. Reuters cites Amnesty International as having found evidence that the PMF have committed “serious human rights violations” against Sunni civilians they “liberated” from the Islamic State in other parts of Iraq, including Fallujah.

The Pentagon had flatly denied the Shiite militias’ participation in the Mosul operation, noting that the U.S. is only aiding the Sunni minority within the PMF. Regarding reports of Hezbollah operatives on the battlefield outside of Mosul, a Pentagon spokesman told Breitbart News, “We have no information on this.”

“The Shiite PMF are not going into Mosul,” Army Maj. Gen. Gary J. Volesky told reporters last week.

The militia fighters who spoke to Reuters rejected this claim and reports of their human rights violations, claiming that they have vowed to eliminate the Islamic State, not attack civilians. “It’s not right what they say about us. When they call us militias it’s like they are insulting us,” one fighter told the news organization.

Speaking to the Kurdish outlet Rudaw (Kurdish Muslims are predominantly Sunni), Shiite commander Karim al-Nuri emphasized his rejection of attacks on Sunni civilians. “We fight and sacrifice for our Sunni brothers. Daesh (ISIS) does not represent Sunnis. Before being an enemy of Shiites, Daesh is an enemy of the Sunnis,” Rudaw quotes him as stating. Al-Nuri also claims the militias will not enter Mosul, instead focusing on blocking the path connecting Mosul to the Islamic State capital, Raqqa, Syria.

Al-Nuri told Rudaw that he rejects the participation of the United States in the operation, however. “We do not need the global coalition because if there is any airstrike done by mistake, people will consider it was done deliberately. Therefore, we do not think it is a good thing for the global coalition to take part,” he protested.

Shiite militias have previously threatened to attack any U.S. forces participating in attacks on the Islamic State. “If the U.S. administration doesn’t withdraw its forces immediately, we will deal with them as forces of occupation,” the PMF said in an official statement in March.

Earlier this month, a Shiite militia leader described the liberation of Mosul as an operation “against the killers of [dictator Saddam] Hussein,” who the United States captured and eliminated as part of the post-September 11 War on Terror.

Asked about the dubious nature of the PMF, Pentagon press secretary Peter Cook said earlier this month that having them involved “has been a uniting thing for Iraq. We think that’s a good thing.” In the same press conference, Cook confirmed that American ground troops “are in harm’s way” as part of the Mosul operation.