KIRKUK, Iraq (AFP) ― Iraq was massing forces Wednesday for an operation to break a two-month jihadist siege of a Shiite Turkmen town north of Baghdad, amid growing fears for residents short of supplies.

The planned counteroffensive around the Salaheddin province town of Amerli comes amid reports that U.S. President Barack Obama is weighing a decision to authorize air strikes and aid drops in the area to help thousands of trapped civilians.

According to a civilian volunteer commander, thousands of Shiite militiamen from groups including Asaib Ahl al-Haq and the Badr Organization are gathering in the Tuz Khurmatu area, north of Amerli, in preparation for a battle to break the siege.

And an army lieutenant general said that security forces were mobilizing in the Jabal Hamreen area, south of Amerli, to launch an attack.

Iraqi aircraft have begun targeting positions of Islamic State jihadists around the town, carrying out nine strikes Tuesday, an officer said.

Time is running out for the town’s residents, who face danger both because of their Shiite faith, which jihadists consider heresy, and their resistance against the militants, which has drawn deadly retribution elsewhere.

There is “no possibility of evacuating them so far,” and only limited humanitarian assistance is reaching the town, said Eliana Nabaa, spokeswoman for the U.N. mission in Iraq.

U.N. Iraq envoy Nickolay Mladenov has called for an urgent effort to help Amerli, saying residents face a “possible massacre” if the town is overrun.

People trapped in the city are suffering from a serious shortage of food and water and there is no electricity.

The sweeping violence in Iraq has displaced hundreds of thousands of people, prompting a massive relief operation by aid organizations.

On Wednesday, the World Food Program said it has delivered assistance to 700,000 people in Iraq since June.

Meanwhile, the New York Times reported that Obama is “nearing a decision” on authorizing strikes and aid drops in the Amerli area.

The paper said that Obama was also seeking to piece together an international coalition for potential military action in Syria, where the U.S. has begun reconnaissance flights to track IS militants.

The U.S. focus on Syria comes after President Bashar al-Assad’s regime said on Monday it was willing to work with the international community, including Washington, to tackle extremist fighters.

But U.S. officials said they did not plan to coordinate with Damascus on targeting IS militants in Syria, despite Syrian insistence that any military action on its soil must be discussed in advance.

International concern about IS has been rising after a lightning offensive by the group through parts of Iraq and a string of brutal abuses, including the murder of U.S. journalist James Foley.

A U.N.-mandated probe charged Wednesday that public executions, amputations, lashings and mock crucifixions have become a regular fixture in jihadist-controlled areas of Syria.

“In areas of Syria under (IS) control, particularly in the north and northeast of the country, Fridays are regularly marked by executions, amputations and lashings in public squares,” the independent Commission of Inquiry on the human rights situation in Syria said.

Jihadists are also pushing residents, including children, to attend public executions by beheading or a shot to the head, it said.

“Executions in public spaces have become a common spectacle on Fridays,” said the report, which also accused Damascus of using chemical weapons against civilians.

The U.S. began air raids against IS in Iraq on Aug. 8. At least nine governments have now committed to providing arms to Iraq’s Kurdish peshmerga troops, who are fighting IS militants in the north.

Pentagon chief Chuck Hagel put the number of countries on board at eight, while Kurdish regional president Massud Barzani said that Iran has provided arms and equipment as well, bringing the total to at least nine.

U.S. chairman of the Joint Chiefs of Staff Gen. Martin Dempsey has acknowledged that the IS group cannot be defeated “without addressing that part of the organization that resides in Syria.”

Syria’s forces on Wednesday lost further ground to other rebels, who seized control of the Syrian side of the sole crossing over the armistice line to the Israeli-occupied Golan Heights, a monitoring group said.

The takeover of the Quneitra crossing was led by al-Qaida’s Syria affiliate Al-Nusra Front, the Syrian Observatory for Human Rights said.

At least 20 Syrian soldiers and four rebels were killed in the fighting, the Britain-based monitoring group said.

“Heavy fighting with the Syrian army is continuing in the surrounding area,” its director Rami Abdel Rahman added.