Beirut: At least 300 Kurdish fighters crossed from Turkey into Syria overnight to battle militants from Isil trying to seize a strategic border town, a monitor said on Saturday.

The Syrian Observatory for Human Rights said the Kurds had joined the Syrian Kurdish People’s Protection Units (YPG) in their fight against Isil as it seeks to capture the town of Ain Al Arab, known as Kobane to the Kurds.

The fighting around the strategic town has prompted a mass exodus into Turkey, which opened its border on Friday to fleeing Kurds and has since received 45,000 people, according to officials.

The clashes broke out on Tuesday evening, and the Isil militants have since seized 60 Kurdish villages in a lightening campaign.

Ain Al Arab is Syria’s third largest Kurdish town and capturing it would give Isil control of a long stretch of the country’s northern border with Turkey.

The Observatory said fighting was continuing on Saturday, with heavy clashes in the vicinity of the town.

Meanwhile. some 45,000 Syrian Kurds fleeing advancing Isil militants have poured across the border into Turkey since Ankara opened up its southern frontier on Friday, the country’s deputy prime minister said.

“As of now, 45,000 Syrian Kurds have crossed the border and entered the Turkish soil from eight entrance points,” Numan Kurtulmus told reporters on Saturday.

“No country in the world can take in 45,000 refugees in one night, bring them here unharmed and find them a shelter without a problem. This proves how powerful Turkey is,” he said.

Syrian Kurds have been massing since Thursday on the other side of the border as the Isil extremists seized dozens of villages in a lightning offensive as they close in Ain Al Arab.

Turkey opened its border on Friday after new fighting near Kobane prompted a mass exodus of residents.

Ankara, which has given shelter to some 1.5 million refugees from the Syrian conflict, has been refusing to accept any more for fear of being overwhelmed.