British Nimrod naval reconnaissance aircraft are flying land surveillance missions in Iraq as part of operations to defeat the use of roadside bombs against coalition troops. Nine Nimrods have been equipped with infrared (night vision) sensors and cameras to patrol Iraqi roads at night looking for anyone who seems to be planting bombs. When someone is spotted, the Nimrod radios nearby ground troops ("reaction forces") waiting to rush out and make arrests and deal with any bombs found. In the last three weeks, these efforts have discovered 15 such bombs. The Nimrod is similar to the American P-3, except that the Nimrod has jet engines instead of propellers. Some P-3s have also been equipped for land surveillance, and used in that role in Afghanistan and Iraq. The Nimrods and P-3s actually specialized in hunting for submarines, but since the end of the Cold War, and the decline of the Soviet submarine fleet, they have had to look for new work or be disbanded.