Turkey has seen tens of thousands of Syrian Kurds crossing its borders after it opened its frontiers to refugees fleeing an advance by the jihadist militant group "Islamic State" (IS), Turkish Deputy Prime Minister Numan Kurtulmus said on Saturday.

"Around 45,000 Syrian Kurds have crossed the border as of now from eight entrance points along a 30 kilometer (18 mile) distance from Akcakale to Mursitpinar since we opened the border yesterday," Kurtulmus told CNN Turk television.

According to Britain-based Syrian opposition group the Syrian Observatory for Human Rights, IS militants have seized some 60 Kurdish villages near Syria's border with Turkey over the past 48 hours amid a rapid offensive.

The advance by the militant group in northern Syria has prompted calls for help by the region's Kurds, who say they fear a possible massacre in the town of Ayn al-Arab, known in Kurdish as Kobani, close to the Turkish border.

At least 18 IS fighters were killed in clashes with Kurds near the town overnight, the Observatory said. Fighting reportedly has continued into Saturday.

International military action

Iraqi Kurdish leader Masoud Barzani on Friday also called on the international community to help Syrian Kurds, saying the jihadists must be "hit and destroyed wherever they are."

The United States is drawing up plans for military action in Syria against the radical Sunni Muslim group, formerly known as ISIS or ISIL, which has taken over large areas in Syria and Iraq.

In Iraq, US aircraft have been carrying out strikes on the insurgents since August 8, being joined on Friday by French warplanes that dropped bombs on a "logistics depot of the terrorist organization," according to French President Francois Hollande.

US President Barack Obama has said he is keen to build an international coalition to combat the jihadist insurgency.

tj/se (Reuters, AFP, AP)