The Army is mobilizing some 5,600 members of the Individual Ready Reserve in three increments from July through December. Col. Debra Cook, commander of the Army Human Resources Command, said those selected will be given 30 days to report, and will receive a minimum of 30 days of training. The orders call for 18 months of active duty, with possible extensions to 24 months. Mailgrams notifying them to expect mobilization orders within a week could already have hit some mailboxes, according to Army officials. Skills needed include military police, mechanics, truck drivers, combat engineers, supply clerks, carpentry and masonry specialists, food service personnel and cable system installers. Retired Soldiers and pregnant Soldiers are exempt, said the Army. As of June 22, the IRR contained slightly more than 111,000 Soldiers. In addition to the IRR callup, 4,000 Army National Guard and Reserve members will be activated, said officials.