Turkish troops take position in the southeastern town of Suruc, Sanliurfa province, near the Mursitpinar border crossing with Syria on Friday. Turkey will do whatever it can to prevent the Syrian Kurdish town of Ain al-Arab, known as Kobane by the Kurds, from falling to jihadists, Prime Minister Ahmet Davutoglu said.

Reuters/Suruc, Turkey/Beirut

The main Kurdish armed group in Syria called on its kinsmen across the region to help it stop a massacre in the Syrian town of Kobani as Islamic State militants armed with tanks edged closer on its outskirts and pummelled it with artillery fire.

Islamic State's battlefield gains in recent months have come as Syrian President Bashar al-Assad's forces have focused on other rebel groups. On Friday the army advanced on the city of Aleppo further west, threatening rebel supply lines in a potentially major reversal.

US-led forces have been bombing Islamic State targets in Syria and Iraq but the action has done little to stop the group's advance in northern Syria towards the Turkish border, piling pressure on Ankara to intervene.

Canada said it would send fighter jets and other aircraft to take part in the US-led strikes on Islamic State in Iraq for a period of up to six months.

Turkey said it would do what it could to prevent Kobani, a predominantly Kurdish town just over its southern border, from falling into Islamic State. It has stopped short of committing to any direct military intervention and Syria warned on Friday against any Turkish "aggression" on its territory.

A statement issued by the YPG, the main Kurdish armed group, vowed "never ending" resistance to Islamic State in its advance on Kobani. "Every street and house will be a grave for them."

"Our call to all the young men and women of Kurdistan ... is to come to be part of this resistance."

Esmat al-Sheikh, head of the Kurdish forces defending Kobani, said the distance between his fighters and the insurgents was now less than one kilometre.

"We are in a small, besieged area. No reinforcements reached us and the borders are closed," he told Reuters by phone. "My expectation is for general killing, massacres and destruction."

Islamic State has carved out swathes of eastern Syria and western Iraq in a drive to create a caliphate between the Euphrates and the Tigris rivers. Kobani's resistance has prevented it from consolidating territory across Syria's north.

Fighting continued after the sunset, with artillery strikes on residential areas east and southwest of Kobani's centre. Kurds returned fire, and red tracer bullets targeting Islamic State strongholds east of the city flew over rooftops, a Reuters correspondent on the Turkish side of the border said.

Remzi Savas, 53, smoked a cigarette and listened to the gunfire over the border.

"My son is over there, he crossed through a minefield to get there. He is just 14. There are many children fighting for the YPG, we can't hold them back. They think they'll lose everything if Kobani falls."

The British-based Syrian Observatory for Human Rights said at least 80 shells had hit the town, known as Ayn al-Arab in Arabic, and there were heavy clashes in the east and southeast.

The fighting has driven Kurds from across northern Syria from their homes across the border into Turkey.