Tripoli: Libyan rebels have started work to get the capital up and running again, as a gruesome find near a base of Muammar Gaddafi's elite troops appeared to highlight the brutality of his regime.

Rebel fighters said on Saturday they had captured the base of the elite 32 Brigade, commanded by Gaddafi's son Khamis, after a NATO airstrike and seven hours of fierce fighting.

In a building nearby correspondent saw the charred remains of some 50 people who residents said were captives killed on Tuesday with rifles and grenades.

National Transitional Council (NTC) chief Mustafa Abdel Jalil, meanwhile, promised the elusive Gaddafi and his senior aides they would be given a fair trial in Libya if they surrendered.

Speaking in the eastern city of Benghazi, where the rebellion began in February, Abdel Jalil also called for emergency humanitarian aid for the capital, stressing the need for medical supplies.

"We are calling all the humanitarian organisations and telling them that Tripoli needs medicines, first aid products and surgical material," he told a news conference.

Blaming "sabotage by Gaddafi's forces" for shortages of water and electricity in Tripoli, he said, "We are working on resolving these problems."

While fighting was still under way on various fronts, the focus was increasingly turning to a post-Gaddafi era, with calls for reconciliation and a peaceful transition.

NTC spokesman Mahmud Shammam said in the capital the rebels would start distributing 30,000 tons of petrol to Tripoli residents immediately, and would be providing cooking gas within the next 48 hours.