Islamic extremists would "try to exploit" any vacuum in the country after four decades of Muammar Gaddafi's rule, Anders Fogh Rasmussen, Secretary General of the NATO told the Daily Telegraph.
The NATO chief's warning follows recent alerts sounded by American intelligence agencies of growing Islamic extremism in neighbouring Egypt as also in Yemen, which have been part of ''Arab spring'' movements.
Telegraph said Rasmussen sounded the alert amid growing evidence of splits in the rebel leadership in Tripoli and his words are bound to dampen euphoria sweeping Libya in the wake of the revolution.
His words were echoed by the head of the National Transitional Council Mustafa Abdul Jalil who told his first mass address in Tripoli last night that the rebels would strive for a moderate Islamic rule in the country.
Jalil, who only arrived in Tripoli on Saturday made his first public speech in Martyrs'' Square -- once Gaddafi's Green Square.
"We are Muslim people, for a moderate Islam and will stay on the road," he said in formulation suggesting that Libya would follow neighbours such as Egypt in allowing room for secular freedom.
But, The Telegraph said there are already signs that the rebel leadership is split over issues including the future role of Islamist militias, which have played a significant role in the downfall of Gaddafi.
All eyes are now on Jalil and the formation of his new interim government with the West watching what quarter the NTC gives to the Islamists and how the radicals behave in the new setup.
Besides the Islamists, the new regime faces threats from Gaddafi himself, whose loyalists are still entrenched in large parts of the oil-rich North African nation.