TRIPOLI -- Colonel Muammar Qaddafi is sheltering in a different hospital in Tripoli each night as he tries to hide from a more aggressive phase of the military operation in Libya, diplomatic sources said Thursday.

The Libyan leader is apparently switching location to increase his safety and seeks haven in hospitals because NATO operations are banned from causing unnecessary civilian casualties under their rules of engagement.

Sources told The Times of London that his behavior, coupled with reports that senior Libyan commanders have stopped using their cell phones, showed that the Libyan regime was under pressure. They added that Colonel Qaddafi appeared to be "quite paranoid."

Libyan prime minister Baghdadi al-Mahmoudi on Thursday asked the UN and the African Union to set a specific date for a cease-fire and requested international observers, but ruled out the departure of Qaddafi.

On Thursday night British officials confirmed that ministers had given permission "in principle" for four Apache attack helicopters to join the conflict. They are expected to be used next week, amid suggestions that the decision has seriously stretched British military capability.

In Deauville, France, President Nicolas Sarkozy is expected to use the second day of the G-8 summit to announce a £1 billion-plus ($1.63 billion) aid package for North Africa and the Middle East. This will include a £110 million contribution over four years from Britain.

Behind the scenes, the French were lobbying for a dramatic change in US policy, which has been heavily criticized since President Obama pulled his forces back into a support role days after the no-fly zone over Libya was imposed.

"We have to increase the pressure and we still believe the US has assets that could make a difference," one diplomat said at the G-8 meetings Thursday. Referring to Obama's current strategy, he added, "We're just saying, maybe we can reconsider this to tip the balance." They want the US to allow the use of A10 Warthog "tankbuster" aircraft and heavily armed AC130 Specter gunships.

It also emerged Thursday that United Nations' peacekeepers were prepared to deploy to Libya if asked to monitor any cease-fire. Such a move could result in hundreds of foreign troops patrolling towns and cities across the country.