BEIRUT: The Syrian army and its allies have secured the Palmyra to Deir al-Zor road, a major supply route from government territory to the eastern city, defeating a strong Daesh (ISIS) attack, a military media unit run by Hezbollah said Friday. Daesh’s assault, which began Thursday, marks the first major counterattack against the Syrian army and its allies since they broke through a swath of territory to reach the city of Deir al-Zor earlier this month.

The Britain-based Syrian Observatory for Human Rights said the Daesh attacks had killed more than 73 fighters from the Syrian army and allied forces since Thursday. The military unit said Syrian forces and allies repelled the attack.

The militant group said it has killed about 40 Syrian soldiers and 10 Hezbollah fighters south of the town of Sukhneh, located on the road to Deir al-Zor, and captured several positions.

“The Syrian army and its allies completely secured the Deir al-Zor-Palmyra highway after foiling the intense attack on their positions in the towns of Al-Shoula and Kabajb,” the Hezbollah media unit said. “The highway has become passable for traffic in both directions to and from Deir al-Zor,” it added.

Earlier Friday, a commander in the military alliance backing Assad said the road linking Deir al-Zor to Palmyra was only being used in cases of absolute necessity and that the army and its allies were fighting to recover lost ground.

Daesh had succeeded in capturing Al-Shoula, which sits on the highway, in its attack.

Helped by the Russian military and Iran-backed fighters, the Syrian army’s advance to Deir al-Zor lifted a three-year-long siege imposed by Daesh on a government-held enclave in the city.

A U.S.-backed alliance of Syrian fighters, the Syrian Democratic Forces, is waging a separate offensive against Daesh in Deir al-Zor to the east of the Euphrates River, which bisects the province.

Daesh leader Abu Bakr al-Baghdadi encouraged his followers to “stand fast” and keep fighting, in an undated recorded statement released Thursday.

In northern Syria, meanwhile, airstrikes hit towns and villages in Idlib, Hama and Aleppo provinces killing and wounding dozens of people, opposition activists and pro-government media said.

Insurgents last week clashed with Syrian and Russian troops in the three provinces.

Rami Abdel-Rahman, the Observatory’s chief, said 42 towns and villages were aerially bombarded on Friday alone, killing at least 12 and wounding 31.

Opposition activists say Syrian and Russian warplanes have been bombing northern Syria for nearly a week, killing as many as 150 people. with Agencies