He says they have not yet found Gadhafi but "the fighters will turn over every stone to find him, to arrest him, and to put him in the court."
Jubilant rebel fighters swept into the heart of Tripoli as Muammar Gaddafi's forces collapsed and crowds took to the streets to celebrate what they saw as the rapidly approaching end of his four decades of absolute power.
Rebels waving opposition flags and firing into the air drove into Green Square, a symbolic showcase the government had until recently used for mass demonstrations in support of the now embattled Gaddafi. Rebels immediately began calling it Martyrs Square.
Two of Gaddafi's sons were captured by the rebels, but the whereabouts of Gaddafi himself were unknown.
U.S. President Barack Obama said Gaddafi's rule was showing signs of collapse and called on him to quit now to avoid further bloodshed.
Laila Jawad, 36, who works at a Tripoli nursery, told Reuters: "We are about to be delivered from the tyrant's rule. It's a new thing for me. I am very optimistic. Praise be to God."
The rebels made their entrance into the capital driving in convoy through a western neighbourhood.
A rebel spokesman said the rebels now controlled over 95 percent of Tripoli, including the Libyan state radio building.
Remaining defiant, Gaddafi earlier had made two audio addresses over state television calling on Libyans to fight off the rebels.
"I am afraid if we don't act, they will burn Tripoli," he said. "There will be no more water, food, electricity or freedom."
But resistance to the rebels appeared to have largely faded away, allowing the rebels and their supporters to demonstrate in Green Square.
Libyans kissed the ground in gratitude for what some called a "blessed day".
Near Green Square youths burned the green flags of the Gaddafi government and raised the rebel flag. One rebel fighter from the Western mountain said: "We are so happy -- we made it here without any problems."
Many Tripoli residents received a text message from the rebel leadership saying: "God is Great. We congratulate the Libyan people on the fall of Muammar Gaddafi."
A member of the rebel leadersip said they would send a special brigade to mop up remaining pockets of government forces after reports of sniping from rooftops, Al Jazeera television said.
Gaddafi, a colourful and often brutal autocrat who has ruled Libya for more than 40 years, said he was breaking out weapons stores to arm the population. His spokesman, Moussa Ibrahim, predicted a violent reckoning by the rebels.
"A massacre will be committed inside Tripoli if one side wins now, because the rebels have come with such hatred, such vendetta...Even if the leader leaves or steps down now, there will be a massacre."
Obama, on vacation in the island of Martha's Vineyard, said in a statement: "The surest way for the bloodshed to end is simple: Muammar Gaddafi and his regime need to recognize that their rule has come to an end. Gaddafi needs to acknowledge the reality that he no longer controls Libya. He needs to relinquish power once and for all."
NATO, which has backed the rebels with a bombing campaign, said the transition of power in Libya must be peaceful.
TRIPOLI FALLS QUICKLY
After a six-month civil war, the fall of Tripoli came quickly, with a carefully orchestrated uprising launched on Saturday night to coincide with the advance of rebel troops on three fronts. Fighting broke out after the call to prayer from the minarets of the mosques.
