The Air Force has begun using armed drones to strike targets in southern Iraq, the military's top officer said yesterday.

The pilotless Predators fly in conjunction with Air Force fighter jets that have been patrolling the "no-fly" zone over southern Iraq for more than a decade, said Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff. Armed Predators began flying over Iraq about a month ago, another officer said.

Myers told reporters that the Predators, which usually are unarmed for low-altitude surveillance, have been effective in Iraq.

One advantage of the Predators is their ability to linger over a target without risking the loss of a pilot. Another is that an armed Predator can respond immediately when it detects hostile Iraqi action, Myers said.

Predators on patrol over the no-fly zone have detected Iraqi gunners firing surface-to-air missiles or antiaircraft artillery, Myers said. The Predator, with its sophisticated sensors, can watch the Iraqi reaction and then launch a Hellfire missile.

Although the missiles are small -- they were developed to attack tanks -- they can be effective against some targets, Myers said.

Predators have been used extensively in the war in Afghanistan. The CIA, the first agency to mount a Hellfire missile on a Predator, used one in a November attack that killed Mohammed Atef, Osama bin Laden's second-in-command.

The unmanned Air Force drone called the Predator, armed with Hellfire missiles, is flying with fighter jets over the southern restricted zone in Iraq.