In an offensive air strikes backed by the U.S.-led coalition, Kurdish Iraqi Peshmerga fighters launched an assault on the strategic town of Sinjar on Thursday aiming to retake the town from ISIS terrorists which had captured it last year, resulting in thousands of Yazidis to flee.

A statement from the Kurdish Regional Security Council said some 7,500 Peshmerga fighters were closing in on the mountain town from three fronts in an effort to take control of the town and cut off a strategic supply line used by ISIS militants.

Peshmerga fighters and ISIS terrorists exchanged heavy gunfire in the early hours Thursday as Kurdish fighters began their approach.

"(Peshmerga) troops are holding their position, waiting for reinforcements and more airstrikes so they can then move into the center of the town. Airstrikes have been very important to the operation getting to the point where it is now," said Maj. Gen. Seme Busal, commander of one of the front lines.

He said Peshmerga fighters were in a similar position on the other front lines, waiting for reinforcements or more airstrikes in order to push into the more urban areas of Sinjar.

Capt. Bawer Azad on the central front line said the troops were coordinating their movements, "We are updating each other on the location and who is making advances where and who is in what place."

The major objective of the offensive is to cut off one of ISIS's most active supply lines, Highway 47, which passes by Sinjar and indirectly links the militants' two biggest strongholds Raqqa in Syria and Mosul in northern Iraq as a route for goods, weapons and fighters.

"If you take out this major road, that is going to slow down the movement of (ISIS's quick reaction force) elements," Capt. Chance McCraw, a military intelligence officer with the U.S. coalition, told journalists Wednesday.

"If they're trying to move from Raqqa over to Mosul, they're going to have to take these back roads and go through the desert, and it's going take hours, maybe days longer to get across," Capt. McCraw said.

Meanwhile, tensions continue to escalate between the Kurdistan Democratic Party (KDP) and the PKK terrorists in Sinjar. Yezidi Peshmerga Commander, Kasim Şeşo, known as a figure with close links to KDP, criticized a statement released by the Sinjar Yezidi Council stating their opposition to KDP's governance in Sinjar. Şeşo said that the Council was founded by the PKK and is not an establishment representative of the Yazidi Kurds.

"As Yazidi Kurds, we will not take orders from anyone other than Masoud Barzani. The Yazidi Council is founded by the PKK. They claim to be representative of Yazidi Kurds, with a few fighters they have on their side. PKK's policies put roadblocks in liberation of Sinjar. We are ready to fight against any assault, but we will not let PKK stay here. PKK has no business here," Şeşo said.

Warplanes in the U.S.-led coalition have been striking around Sinjar ahead of the offensive and strikes grew more intense at dawn Thursday as bombs pounded targets outside the town. But Sinjar, located at the foot of Sinjar Mountain about 30 miles (50 kilometers) from the Syrian border, is not an easy target. One attempt by the Kurds to retake it stalled in December. The militants have been reinforcing their ranks in Sinjar recently in expectation of an assault, since "this operation has been building for a while," Maj. Michael Filanowski, operations officer for the U.S.-led coalition, said Wednesday, though he could not give specifics on the size of the ISIS terrorists there.

Sinjar was captured by the ISIS group in August 2014 shortly after the extremists seized Iraq's second-largest city, Mosul, and blitzed across northern Iraq.