Islamic State fighters pushed into two districts of the strategically important Syrian border town of Kobani in fierce fighting late on Wednesday, Kurdish officials among the town's defenders said."Tonight (Islamic State) has entered two districts with heavy weapons, including tanks. Civilians may have died because there are very intense clashes," Asya Abdullah, co-chair of the Democratic Union Party (PYD), the main Syrian Kurdish group defending the area, told Reuters from the town.Another PYD official said that despite continuing US-led coalition airstrikes on Wednesday evening Islamic State fighters had seized some buildings on the eastern edges of the town.The militants were being held in the suburbs by fierce resistance from Kurdish forces defending the town, which has been under assault for more than three weeks, the official added. US Secretary of State John Kerry suggested on Wednesday that preventing the fall of the Syrian town of Kobani to Islamic State fighters was not a strategic US objective and said the idea of a buffer zone should be thoroughly studied."As horrific as it is to watch in real time what is happening in Kobani ... you have to step back and understand the strategic objective," Kerry told reporters at a news conference with British Foreign Secretary Philip Hammond."Notwithstanding the crisis in Kobani, the original targets of our efforts have been the command and control centers, the infrastructure," he said. "We are trying to deprive the (Islamic State) of the overall ability to wage this, not just in Kobani but throughout Syria and into Iraq."Kerry also said that he expected Turkey, which has demanded a no-fly zone, a buffer zone in Syria and greater effort against the forces of Syrian President Bashar Assad, to decide "over the next hours, days" what role it may play against the Islamic State group, which the US government refers to as ISIL.France said on Wednesday it supported the idea of setting up a buffer zone between Turkey and Syria to create a safe haven for displaced people, President Francois Hollande's office said after he spoke to his Turkish counterpart.Britain's Hammond reacted cautiously to the idea, as did Kerry, noting that it has been proposed for some time and saying it deserved close study."The idea of a buffer zone is one that has been floated. We have to explore with our other allies and partners what is meant by a buffer zone and how such a concept would work, but I certainly wouldn't want to rule it out at this stage," Hammond told reporters."The buffer zone is an idea that has been out there. It is worth examining, it's worth looking at very, very closely," Kerry said, largely echoing the unenthusiastic stance that the United States has taken toward the proposal.