WASHINGTON — The Pentagon is blaming bad weather for the crash landing in Afghanistan of a U.S. special forces helicopter that injured four of its crew, and for the loss of an unmanned spy plane.

The helicopter was sent at night to pick up a sick soldier, said a senior government official, speaking on condition of anonymity. It crashed at about 1:30 p.m. EST Friday, the U.S. military said.

The injured crew members were rescued by a second helicopter that had accompanied them on their initial mission. The injuries were not considered life-threatening and the crew was receiving medical care, a Pentagon spokesman, Air Force Maj. Mike Halbig, said Saturday.

He declined to say where the U.S. helicopters had come from or where the injured men were taken, and said he could not offer any details on the type of helicopters involved in the mission.

``The entire crew has been safely recovered out of Afghanistan,'' according to a military statement.

F-14 Tomcats from the USS Theodore Roosevelt, one of the U.S. aircraft carriers off Pakistan, were sent in later to destroy the damaged helicopter that crashed.

Such a search-and-destroy mission would only take place if the items on the helicopter were considered extremely sensitive and the U.S. military did not want it to fall into enemy hands.

Special forces teams are helping anti-Taliban rebels with training and tactics and are directing American warplanes to Taliban targets. The United States has troops in Uzbekistan, including members of the Army's 10th Mountain Division.

Halbig denied Taliban claims that they shot down the helicopter, and that dozens of soldiers were involved.

``It's false. As many claims with the Taliban, it is simply not true,'' he said.

The unarmed Air force RQ-1B Predator was reported missing Friday at approximately 2:15 p.m. EST. ``Preliminary reports indicate that severe weather contributed to the loss,'' said a statement released at the Pentagon and issued by the U.S. Central Command.

For days, Pentagon officials have complained that freezing rain and fog have hampered operations in northern Afghanistan.

The spy plane is part of the military effort to attack the al-Qaida terrorists and the Taliban regime harboring them.

Halbig said there were no indications that the Predator had been shot down, either, but that ``severe weather contributed to the loss.''

The United States said it was the military's first unmanned aerial craft lost in the anti-terrorism effort in Afghanistan.

In late September, Defense Secretary Donald Rumsfeld acknowledged in that another such craft had apparently gone down. That aircraft, however, was believed to have been operated not by the Pentagon but a different government agency.

These latest incidents occurred as the military enters the fourth week of its bombing campaign, meant to destroy Osama bin Laden's terrorist network.

President Bush said Friday that the airstrikes will not pause during the Muslim holy month of Ramadan, which begins around Nov. 17.

``The enemy won't rest during Ramadan and neither will we,'' Bush said. ``We're going to pursue this war until we achieve our objectives.''

He chided critics who are demanding more aggressive U.S. action and said the American people understand the struggle will be a long one.

``This is not an instant gratification war,'' he said.

Rumsfeld was in Moscow on Saturday on the first leg of a five-nation trip that also included Uzbekistan, Tajikistan, Pakistan and India. En route from Washington, Rumsfeld said the Taliban were ``substantially weakened, in many cases cloistered away from the people.'' He said it would be ``mindless'' to slow the military campaign so Afghan factions could agree on an interim post-Taliban government.

``I don't think it's possible to manage the war campaign on the ground under a political timetable,'' Rumsfeld said.