As Islamic State fighters make a last stand against Turkish-backed troops in a key strategic city in northern Syria, IS appears to have few options as to where it can retreat.
As of Thursday morning, anti-IS forces were in control of the northern part of the town of al-Bab amid fierce clashes with the remaining IS fighters. Local reports said fighting also was taking place in the center of the town.
There are nearly 1,000 IS fighters left in al-Bab and 800 others on the outskirts, according to Abu Eyad, a rebel fighter who is involved in the Turkish-backed operation. "These fighters are mostly foreigners and they are likely to fight in al-Bab until they die," Eyad said.
IS has suffered blows from ground troops on several sides around al-Bab, including on the southern front where Syrian troops have closed in and are only three kilometers away from the town.
U.S. airstrikes in support of Turkish forces and Syrian rebels also have been key in the recent advances in al-Bab.
IS loss ‘inevitable’
IS fighters "are putting up a tough fight in and around al-Bab," said Ahed al-Hendi, a Syrian affairs analyst in Washington.
But, he said, IS knows "that its loss there is inevitable, so they will fight until the end."
At least 10 Turkish soldiers have been killed by IS since clashes intensified Wednesday morning.
Similar to previous battles where it lost territory, IS "will carry suicide bombing attacks on [Turkish] soldiers and use civilians as shields," said Metehan Demir, a Turkish military affairs analyst in Ankara.
Under siege in Iraq, and also in its de facto Syrian capital in Raqqa, IS is becoming hemmed in on several fronts, analysts say. IS fighters who survive in al-Bab have one safe haven left in Syria.
"They will need additional fighters to be in Raqqa as the Kurdish-led forces are advancing very rapidly from the north and west," analyst al-Hendi said. "So any retreating force from al-Bab will be deployed to Raqqa."
Looking toward Raqqa
U.S.-backed Syrian Democratic Forces have made new advances against IS fighters this week after launching a third phase of their ongoing offensive to retake Raqqa, some 200 kilometers east of al-Bab.
U.S. military officials say it is a matter of weeks before Raqqa is besieged.
"What we would expect is that within the next few weeks, is that the city would be nearly completely isolated and then there will be a decision point to move in," said Colonel John Dorrian, a spokesman for the U.S.-led coalition against IS.
In anticipation of an imminent attack on Raqqa, analysts said, IS will continue to build its defensive lines there.
"If the remaining IS fighters in al-Bab stay alive, they will go to defend Raqqa," Turkish analyst Demir said.