Iran is sending special forces to Iraq to help Baghdad halt militants advancing on the capital, the Times of London reported on Friday.

The predominantly Shiite Muslim nation has reportedly sent a team of 150 elite Revolutionary Guard troops to aide Iraq’s faltering government as it struggles to form a coherent response after the Sunni militants blitzed and captured the country’s second-largest city of Mosul as well as other, smaller communities and military and police bases — often after meeting little resistance from state security forces.

On Thursday President Hassan Rouhani warned Iran will combat the “violence and terrorism” of Sunni extremists in Iraq.

“This is an extremist, terrorist group that is acting savagely,” Rouhani said, without elaborating on what steps Tehran would take to thwart a bid by fighters from the Islamic State of Iraq and the Levant (ISIL) to push toward Baghdad after seizing cities and towns to the north.

The Iranian troops are being led by General Hasan Gohari, a veteran of the Iran-Iraq War in the 1980s. They are expected to advise Iraqi forces on matters of strategy and training.

Military involvement in Iraq would represent a continued widening of Tehran’s sphere of influence over its Middle East neighbors, as it continues to assist and support Syrian President Bashar Assad in quelling the rebellion against his rule — support which seems to have been critical in ensuring Assad’s survival and perhaps even turned the tide of the civil war.

A representative for Iraq’s top Shiite cleric has called on Iraqis to defend their country, saying those who are able should join the security forces to battle the militants.

Sheik Abdul-Mahdi al-Karbalaie made the comments during Friday prayers. He represents Grand Ayatollah Ali al-Sistani, the most revered Shiite spiritual leader in Iraq.

Al-Karbalaie says it is “a duty” that citizens defend against “the dangers threatening Iraq.”

The new reality is the biggest threat to Iraq’s stability since the US withdrawal at the end of 2011, and it has pushed the nation closer to a precipice that could partition it into Sunni, Shiite and Kurdish zones.

Police officials said militants driving in machinegun-mounted pickups entered two towns in Diyala province late Thursday — Jalula, 80 miles northeast of Baghdad, and Sadiyah, 60 miles north of the Iraqi capital.

Iraqi soldiers abandoned their posts there without any resistance, said the officials, speaking on condition of anonymity because they were not authorized to talk to media. The officials also said that Kurdish forces from northern Iraq’s semi-autonomous Kurdish region entered Jalula to secure offices of Kurdish parties in the town but no clashes were reported between the two groups.

Fighters from the Islamic State have vowed to march on Baghdad and are being joined in their rebellion by Saddam Hussein-era loyalists and other disaffected Sunnis.

Three planeloads of Americans were being evacuated from a major Iraqi air base in Sunni territory north of Baghdad, US officials said Thursday, and Germany urged its citizens to immediately leave parts of Iraq, including Baghdad.

President Barack Obama said Iraq will need more help from the United States, but he did not specify what it would be willing to provide. Senior US officials who spoke on condition of anonymity because they were not authorized to discuss the matter by name said Washington is considering whether to conduct drone missions in Iraq.

The UN Security Council met on the crisis, underscoring the growing international alarm over the stunning advances by the Islamic State.