Beirut: Kurdish fighters on Thursday held off a fierce assault by the Islamic State group on the strategic border town of Ras al-Ain in northeast Syria, a monitoring group said.
But the jihadists advanced against the Kurdish militia around Tal Tamr, another key town on the same front line in Syria`s Hasakeh province.
IS launched a major offensive Wednesday to try to capture Ras al-Ain, which has a border crossing with Ceylanpinar in Turkey.
The jihadists want to seize the town, as well as Tal Tamr, to control key routes that link to their Iraqi bastion of Mosul farther east.
"The Islamic State took over the village of Tal Nasri, so they are now only 500 meters (yards) from Tal Tamr," said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.
He said 22 Kurdish fighters and at least 18 IS jihadists had been killed in the battle for Tal Tamr.
Dozens more have been killed in fighting near Ras al-Ain, according to the Britain-based Observatory.
"This is all one operation by the Islamic State. Tal Tamr and Ras al-Ain are the same front," Abdel Rahman said.
The jihadists made a preemptive strike on Ras al-Ain because they feared the Kurds would use it as a launchpad for an attack on the IS-held town of Tal Abyad to the west, the Observatory said.
Tal Abyad is used by jihadists as a gateway from Turkey into the Syrian province of Raqa, home to IS`s self-proclaimed capital.
The IS offensives come just weeks after Kurdish militia backed by Iraqi peshmerga fighters and Syrian rebels drove the extremists out of the key battleground town of Kobane farther west along the Turkish border.
Foreign jihadists have flocked to Syria, often crossing over from Turkey, since the country`s conflict began in March 2011 as a popular revolt which later escalated into a full-blown civil war.