Turkey is preparing to "clean" the Syrian side of the border of DAESH extremists after a Turkish border town came under repeated deadly rocket attacks, President Recep Tayyip Erdoğan said on Thursday."We are making all the necessary preparations to clean the other side of the border because of the problems in Kilis," he said amid persistent speculation of a possible cross-border ground operation, without giving details on the preparations.Around two dozen people have been killed in the Turkish border town of Kilis by rocket fire from DAESH terrorists since January, prompting the military to respond with artillery.Turkey, a member of the U.S.-led coalition battling DAESH, has received almost none of the support it wanted from its allies in the fight against the extremist group and indicated Ankara was prepared to take unilateral action."While our citizens fall dead every day in the streets of Kilis by rockets launched from the other side, what can we expect from our allies? Let me say it here. We will not hesitate to take needed steps on our own if necessary," he said.Erdoğan said what happens in Kilis would be a "litmus test" to show the anti-DAESH coalition's sincerity in dealing with the threat. "We do not believe the sincerity of any country that has not seen rockets falling on our town as if they fell on Moscow, London, Brussels, Washington, Paris or Berlin," he said.Meanwhile, Turkish artillery pounded DAESH targets in northern Syria overnight and the U.S.-led coalition carried out airstrikes, killing 28 militants near Kilis, Turkish military sources said.The artillery strikes near Kilis, north of Aleppo, started at about 8 p.m. and ended in the morning, the sources said. Intelligence reports had suggested the militants were preparing attacks, they said.The airstrikes destroyed a two-story building used by the militants as a base along with 11 fortified defensive positions, they said. The Turkish and coalition operations targeted an area about 10 kilometers south of the border.The Turkish Armed Forces (TSK) have stepped up attacks on DAESH in Syria in recent weeks after rockets fired by the group repeatedly landed in Kilis, in what appeared to be a sustained and deliberate assault. More than a dozen rockets hit the town last week alone.Gunfire and occasional explosions from across the border could be heard on Wednesday from a hill in Kilis, which is home to more than 100,000 Syrian refugees.Erdoğan said on Wednesday that Turkey's armed forces had killed 3,000 DAESH terrorists in Syria and Iraq, where Turkish soldiers are training local forces to fight the insurgents. "While countries [taking part in the anti-DAESH coalition] didn't take any steps, didn't conduct the necessary intelligence-sharing, Turkey was expected to do everything."He also condemned the claims that Turkey supported the group as "despicable.""In fact, during this process, Turkey battled many unfair, ruthless and unfounded accusations," Erdoğan said. "The portrayal of Turkey as a country that helps DAESH is – excuse me if this will sound harsh – despicable."