Updated

The Pentagon would like to move low-flying, deadly AC-130 gunships closer to Northern Afghanistan to support anti-Taliban forces in their battle for control of Kunduz, Defense Secretary Donald H. Rumsfeld said Wednesday.

Also, the Navy has given notice it will stop and board merchant shipping off the coast of Pakistan if the ships are suspected of carrying Usama bin Laden or other Al Qaeda leaders, Pentagon spokesman Lt. Col. Dave Lapan said Wednesday.

Lapan said the notice to mariners was issued Tuesday, but he did not know if any boardings had been conducted.

Rumsfeld would not confirm reports that Uzbekistan has agreed to allow AC-130s to fly from its territory and said none has been based there so far.

"It would be helpful for us to have AC-130s up north, particularly when you have a situation like Kunduz because that particular weapons system and platform can put out an enormous amount of ordnance with a great deal of precision," he told reporters in route to Pope Air Force Base, where he received a tour of an AC-130 on the tarmac.

AC-130s have been used heavily against Taliban and Al Qaeda targets in southern Afghanistan. One of their most fearsome aspects is a pair of 20mm Gatling guns, each of which can fire 2,500 rounds of ammunition per minute.

Rumsfeld also confirmed that the Air Force's new high-altitude unmanned surveillance plane, the Global Hawk, is now operating over Afghanistan for the first time.

A U.S. helicopter crash-landed in southern Afghanistan on Tuesday, injuring four crew members, according to U.S. Central Command which runs the war in Afghanistan. The statement said the cause of the accident is unknown but that it was not due to hostile fire.

A Pentagon spokesman said the injuries, including several broken bones, were not considered life-threatening. The helicopter crew was evacuated and the helicopter removed.

Tuesday's U.S. air strikes concentrated on areas near Kunduz and Kandahar, the two last remaining Taliban strongholds in Afghanistan, Pentagon spokesman Richard McGraw said.

He said aircraft conducted 146 missions over Afghanistan, but did not disclose how many bombed targets. Many of the missions were flown to assist anti-Taliban insurgents.