NEW : Witnesses observe intermittent artillery fire from Syria into U.S. , U.N. reports . Syria says it is investigating source of gunfire fired into Turkey . No evidence of broader conflict , Turkey defense official says . Nine people were injured when the shell landed on the town in Sanliurfa province , near the Syrian border , the Turkish prime minister 's statement said . Turkey strikes targets in Syria following shelling of a Kurdish border town .
NEW : Witnesses observe intermittent artillery fire from Syria into U.S. , U.N. reports . Syria says it is investigating source of gunfire fired into Turkey . No evidence of broader conflict , Turkey defense official says . Turkey strikes targets in Syria following shelling of a Kurdish border town .