Kurdish forces, backed by US air power, have been holding out for weeks against an IS offensive around Kobane, which has become a high-profile symbol of efforts to stop the advance of the jihadists.
The Kurdish regional government in northern Iraq unveiled plans on Friday for up to 200 well-trained peshmerga to join Syrian Kurdish forces defending Kobane in the coming week.
Kurdish news agency Rudaw said the first contingent could head to the town as early as Sunday, but there was no immediate confirmation of that timetable.
Since Turkey conceded to US pressure to allow vetted reinforcements into Kobane to prevent IS winning the prominent battle for the town, the jihadists have made repeated attempts to cut the border before any help can arrive.
Before dawn on Saturday, IS fighters hit Kurdish forces defending the Syrian side of the border crossing with mortar and heavy machinegun fire, an AFP correspondent on the Turkish side reported.
The heavy mortar fire around the Mursitpinar crossing prompted the Turkish army to order the evacuation of nearby hilltops from where the world’s press has been watching the battle for the town.
The US-led military coalition fighting IS launched 22 air strikes in Iraq and one in Syria on Friday and Saturday, the Pentagon said.
Eleven of the bombings in the heavy barrage targeted IS units, buildings, positions and vehicles near Iraq’s strategic Mosul Dam.