Syrian government forces and Kurdish forces have fought separate battles with the Islamic State of Iraq and the Levant (ISIL) group in a strategic area near the Iraqi and Turkish borders, according to a monitoring group.
Forces loyal to President Bashar al-Assad and fighters from the Kurdish People's Protection Units (YPG) launched uncoordinated offensives against ISIL in the northeastern province of al-Hasakah, the Syrian Observatory for Human Rights said on Monday.
Rami Abdel Rahman, the Syrian Observatory head, told AFP news agency that after three days of clashes, regime forces bolstered by fighters from Arab tribes had secured control over 23 villages in the centre of the province from ISIL.
Syria's official news agency SANA put the number at 31.
State television said the army offensive would continue until it controlled the main road linking the provincial capital Hasakah and the city of Qamishli.
"ISIL has launched counter-attacks on regime checkpoints, while the regime fortifies its positions with support from local Arab tribes," Abdel Rahman said.
He said Kurdish fighters were meanwhile also battling ISIL alongside Arab tribes outside the village of Tal Tamr in Hasakah's southwest.
But ISIL has reportedly refused to fire back to avoid giving away their positions.
Redur Khalil, YPG spokesperson, confirmed to AFP that the Kurdish fighters were conducting "attack-and-retreat operations" with ISIL fighters on two fronts.
The YPG militia has been one of ISIL's toughest enemies in Syria, helping flush the group out of Kobane on the Turkish border.
ISIL launched an attack last week on the areas around Kurdish-controlled Tal Tamr and kidnapped 220 Assyrian Christians from 11 villages. Nineteen of them were freed on Sunday after ransoms were paid.
Control of Hasakah province is split between ISIL, regime forces and Kurdish fighters, with overlap at a number of points.
Government forces withdrew from most of the province in the first few months after the start of Syria's uprising in March 2011, granting greater autonomy to the Kurds.
The area is of strategic importance because it borders both Turkey and Iraq.
More than 200,000 people have been killed in Syria's conflict, which began with popular protests against corruption and emergency law and descended into civil war after a crackdown by Assad's security forces.
Source: Al Jazeera and agencies