Secretary-General Ban Ki-moon is deeply concerned about serious risk the ongoing conflict between Syrian Government and opposition forces poses to UNDOF\'s operations and personnel on the ground, his press office said in a statement. \"Safety and security of United Nations personnel is of the highest priority for the United Nations,\" stressed the statement, released early on Friday.  On Thursday, a UN Disengagement Observer Force (UNDOF) convoy carrying troops scheduled to rotate out of the peace-keeping mission in the Golan Heights came under gunfire close to the Damascus International Airport, where military operations between the two sides were taking place. Preliminary information received from UNDOF indicated that at least four UNDOF personnel were injured as a result of the gunfire. It was not the first time the Disengagement Force between Syria and Israel came under fire.