British Foreign Secretary William Hague has arrived in Libya for talks with opposition leaders in the rebel stronghold, Benghazi.

Hague is one of the highest-ranking foreign officials to visit the rebel-held territory. The foreign secretary said he plans to meet with leaders of the Transition National Council on Saturday as part of his efforts to “show support for the Libyan people.” He is accompanied by British International Development Secretary Andrew Mitchell.

Their visit to Libya comes at a time when NATO is employing new strategies for targeting installations linked to Libyan leader Moammar Gadhafi.

For the first time, the alliance sent attack helicopters on low-altitude missions against military installations early Saturday.

NATO said British Apache and French Tiger and Gazelle helicopters carried out the assaults. Military officials said about 20 targets were destroyed, including a radar site and an armed checkpoint, in the first deployment of the aircraft since British and French leaders approved their use in recent days.

The commander of NATO's forces in Libya, Canadian Lieutenant General Charles Bouchard, said the successful assault demonstrates the “unique capabilities” of the attack helicopters. The use of lower-flying helicopters for attacks could diminish the possibility of civilian casualties, although they also could be vulnerable to strikes by surface-to-air missiles.

Despite this increase in the military campaign, there are new diplomatic efforts to try to persuade Mr. Gadhafi to give up power. French Foreign Minister Alain Juppe said Friday that his country is working with those close to the Libyan leader to get him to leave.

Russia is sending a special presidential representative, Mikhail Margelov, to Benghazi, to meet with the rebels.