<p>An explosion was heard Wednesday near a northern Iraqi airport that is close to a base hosting U.S. troops, a statement from the Kurdish region’s Interior Ministry said. </p>
<p>The ministry did not provide further details about the cause of the explosion or any damage or casualties near Irbil international airport. In a statement it said an investigation would take place. </p>
<p>Irbil is located in the northern Kurdish-run semi-autonomous region of Iraq. </p>
<p>It was not immediately clear how close the explosion was close to a base hosting U.S. troops in the vicinity of Irbil airport. Witnesses in Irbil reported hearing sirens and hearing a loud bang. </p>
<p>The development comes as a string of attacks have targeted mostly American installations in Iraq in recent weeks. </p>
<p>Last week, two rockets landed near an Iraqi air base just north of Baghdad where American trainers are present. There were no casualties. </p>
<p>A month earlier, a base in western Iraq housing U.S.-led coalition troops and contractors was also the target of rocket fire. One contractor died after 10 rockets hit the base. </p>