British Apache and French attack helicopters struck targets for the first time in NATO's campaign in Libya, hitting Moammar Gadhafi's troops early Saturday near a key coastal oil city, the alliance said.
The action was a significant step-up in NATO's operations and a major boost to Libyan rebels, just a day after rebel fighters forced government troops from three western towns and broke the siege of a fourth in yet another erosion of Gadhafi's power since the eruption in mid-February of the uprising to end his 42-year rule.
NATO said the helicopters struck troops trying to hide in populated areas, military vehicles and equipment. Lt. Gen. Charles Bouchard, commander of the Libya operation, said the engagement "demonstrates the unique capabilities brought to bear by attack helicopters."
Until now, NATO has relied on attack jets, generally flying above 15,000 feet (4,500 meters) -- nearly three miles (five kilometers) high -- and pounding Gadhafi targets in relentless overnight bombings.
The helicopters give the alliance a key advantage in close-up combat, flying at much lower altitudes.
The Apaches hit two targets near the eastern oil city of Brega, according to a statement from the Ministry of Defense in London. It said they took off from HMS Ocean, stationed off the Libyan coast and returned safely after completing their mission in the early morning hours.
British Maj. Gen. Nick Pope said the Apaches targeted a radar installation and a military checkpoint. "Hellfire missiles and 30mm cannon were used to destroy the targets," he said.
Separately from the helicopters, Royal Air Force aircraft destroyed another military installation near Brega and two ammunition bunkers at the large Waddan depot in central Libya, Pope said.
Brega is of strategic importance to Libya's oil industry and lies on the coastal road along the Mediterranean that leads to the capital, Tripoli. In the early days of the uprising against Gadhafi, it went back and forth between rebel and loyalist hands, but later the front line settled to the east of the city, leaving Brega under Gadhafi's control.
Waddan lies southwest of Brega, about 140 miles (220 kilometers) from the coastline.
The French Gazelle and Tiger model attack helicopters took off from the helicopter transport ship Tonnerre in the Mediterranean, said Col. Thierry Burkhard. He said they struck 15 military vehicles and five military command buildings, without identifying the sites or their location.
Burkhard said the French helicopters came under light-arms fire but were not hit or damaged. The operation was aimed at putting "additional pressure on the Gadhafi forces who continue to threaten the civilian population," he said.
British Defense Secretary Liam Fox said Saturday that the "use of the attack helicopters is a logical extension" in NATO's campaign and indicated more would be used in the future.
"We will continue with the methods we have to degrade his (Gadhafi's) command and control, to degrade his supplies," Fox said from Singapore, where he was attending an Asian security conference.
The helicopter strikes came after Libyan rebels on Friday won control of four towns in the western Nafusa mountain range, where government forces have besieged and randomly shelled rebel-held areas for months.
The small rebel force in the western mountains is unlikely to threaten Gadhafi's hold on Tripoli, 45 miles (70 kilometers) northwest, but the victories could bring relief to local residents by opening up roads between their communities. The western mountain population is tiny compared with the large rebel-held territories in east Libya.
The head of the rebels' Transitional National Council, Mustafa Abdul-Jalil, said the NATO attacks were in accordance with the U.N. resolution that authorized the international air campaign, but emphasized that the Apaches launched outside Libya.
"We welcome any measures to expedite the departure of Moammar Gadhafi but at the same time we maintain the sovereignty of the Libyan state," Abdul-Jalil told reporters on Saturday.
Abdul-Jalil and other rebel political leaders were to meet with visiting British Foreign Secretary William Hague, who arrived Saturday in the rebels' de facto capital, Benghazi. Hague and another British Cabinet minister, International Development Secretary Andrew Mitchell, were also expected to meet with Libyan citizens in a visit that Hague said was meant to show support for those fighting Gadhafi's rule.
Hague is one of the highest-ranking foreign officials to visit rebel-held territory in eastern Libya.
The conflict in Libya appears at a stalemate after nearly four months. NATO airstrikes have kept the outgunned rebels from being overrun, but the rebels have been unable to mount an effective offensive against Gadhafi's better equipped armed forces.
Gadhafi's regime has been slowly crumbling from within. A significant number of army officers and several Cabinet ministers have defected, and most have expressed support for the opposition, but Gadhafi's hold on power shows little sign of loosening.
Gadhafi has been seen in public rarely and heard even less frequently since a NATO airstrike on his compound killed one of his sons on April 30. Questions are arising about the physical and mental state of the 69-year-old dictator, who has ruled Libya since 1969.
Rebels have turned down initiatives calling for cease-fires, insisting that Gadhafi and his sons must relinquish power and leave the country.
Associated Press writers Alex Kennedy in Singapore, David Stringer in London, Jamey Keaten in Paris and Don Melvin in Brussels contributed to this report.