In a message broadcast to supporters, Hassan Nasrallah, the leader of the Lebanese Shia group Hezbollah, announced last week that the militants had a "limited presence" in Iraq as he called upon countries in the Middle East to "come with us" to fight the threat from the Islamic State (IS). It is not the first time Hezbollah has intervened in an Iraqi conflict, but with its battles in Syria and suggestions that the militant group may be overstretched, the nature of its commitment on the Iraqi front lines remains unclear.
Hezbollah, a political and militant organization formed in the 1980s with the help of Iran, is currently fighting with President Bashar Assad's forces against the Syrian rebels. The former Lebanese Prime Minister Saad Hariri recently called for the group to withdraw from the country, accusing them of "destroying Syria on the heads of Syrians." Hezbollah has also been engaged in deadly clashes with the al Nusra front on the mountainous Syrian Lebanese border of Qalamoun. Last month, it clashed with Israel, attacking a military convoy in response to an Israeli air strike.
But last week's announcement was the first time that Nasrallah confirmed Hezbollah's involvement in Iraq.
"We may not have spoken about Iraq before, but we have a limited presence because of the sensitive phase that Iraq is going through," said Nasrallah in a speech to his supporters.
"I say to those who call on us to withdraw from Syria, let's go together to Syria," he said.
"I say, come with us to Iraq, and to any place where we can fight this threat that is threatening our [Muslim] nation and our region."
Commenting on Nasrallah's speech, Alexander Corbeil, an analyst for the think tank SecDev Group, told VICE News: "The growth of ISIS (IS) and Jabhat al-Nusra has in part legitimized the narrative that Hezbollah is fighting radicals in Syria and, by extension, Iraq, to the best interest of states and peoples in the region."
It is thought, however, that Hezbollah has been operating in Iraq in a limited capacity for some time. In July 2014, Hezbollah commander Ibrahim al-Hajj, a technical specialist involved in training, was killed near Mosul, Iraq. Lebanon's the Daily Star reported that Iraqi officials had said that the militant group sent advisers to help Iraqi militias fighting Sunni extremists, and that the commander's death was the first known Hezbollah death in Iraq when IS captured large parts of the country.
The commander's death near Mosul, the northern city which was taken by IS last June, was significant, as it had previously been thought that Hezbollah members were mainly based in Baghdad, away from the front lines. Estimates suggested at the time that around 250 to 500 militants from the group were present in the country.
It is not the first time Hezbollah has become involved in an Iraqi conflict. VICE News spoke to Matthew Levitt of the Washington Institute and author of Hezbollah: The Global Footprint of Lebanon's Party of God, who said: "During the coalition war in Iraq, Hezbollah set up an entire unit dedicated to training and supporting Iraqi Shia militants in their attacks against coalition forces, Unit 3800."
According to an article by Levitt and Nadav Pollak for the Washington Institute, then, Hezbollah's Unit 3800 sent a small number of personnel to Iraq to train hundreds of fighters, while others were brought to Lebanon for more advanced training. A 2010 unclassified military report, available via the Federation of American Scientists, states how, in Iraq, "Lebanese Hizballah provides insurgents with the training, tactics and technology to conduct kidnappings, small unit tactical operations and employ sophisticated IEDs."
But the landscape has now changed. Hezbollah, long an ally of Assad's Shia regime, joined forces with his troops to fight against Syrian rebels in 2013, and have sustained losses, with some suggesting a toll of up to 1,000 fighters . In 2014, there were reports of Iran, Hezbollah's main backer, cutting its funding due to the impact of falling oil prices and Western sanctions on the Islamic Republic's economy.
Speaking to VICE News, Levitt said: "There's no need for them [Iraqi Shia militias] to have [Hezbollah] foot soldiers and nor can Hezbollah afford to send foot soldiers. Hezbollah is committed to large numbers in Syria and what it can do, and all what it can afford to do frankly, and all that the Iraqi Shia militants need, is training, advising and command control."
And Hezbollah's commitment in Syria is large. According to Corbeil, "Hezbollah has an estimated 5,000 fighters in Syria at any given time and must also be on guard in southern Lebanon, ensuring that it cannot make a big battlefield commitment to Iraq."
Whether Hezbollah is sending fighters to the front lines is yet to be seen, but sending technical assistance to Iraqi Shia militias adds to the complexities of the fight against IS.
Follow Jenna Corderoy on Twitter: @JennaCorderoy