Nato intelligence and reconnaissance assets are being used to try to hunt down Moammar Gaddafi, the elusive Libyan dictator.
British Defense Secretary Liam Fox said Nato was playing an active role in efforts to locate Gaddafi, whose whereabouts are unknown. Rebels stormed his compound in the Libyan capital of Tripoli on Tuesday, but he was not there.
The rebel leadership has offered a $2 million bounty on Gaddafi's head, but the autocrat has refused to surrender, fleeing to an unknown destination as his 42-year regime crumbles in the North African nation. Speaking to a local Libyan television channel Wednesday, apparently by phone, Gaddafi vowed from hiding to fight on "until victory or martyrdom."
Fox declined to confirm whether troops from Britain's elite Special Air Service or Special Boat Service were involved in attempts to locate Gaddafi — but acknowledged that Nato has a key role.
"We never comment about special forces, not least because if we were to use them under those circumstances it would compromise their security," Fox told BBC Radio 4.
European officials have confirmed that small numbers of British, French and other special forces have been working inside Libya in recent months.
"It is fair to say, however, that Nato is providing intelligence and reconnaissance assets to help in the hunt for Col. Gaddafi, and indeed the remnants of the regime," Fox said. "Last night, Nato was more active than we have been in recent days in terms of air activity against the resisting elements."
The United States is the largest contributor to Nato, but there was no immediate word from Washington on whether US military resources were being directly used in the hunt for Gaddafi.
US drone aircraft have been helping the Libyan rebels with intelligence-gathering for months, however, and the CIA and other US intelligence agencies have been gathering information from contacts they had developed in Libya before the uprising began last spring against Gaddafi's regime.
Rebels say Gaddafi's hometown of Sirte, which is 250 miles (400 kilometers) east of Tripoli on the Mediterranean Sea, is now a key target. Mahmoud Jibril, the head of the opposition government, said Wednesday during talks in Paris that Gadhafi could be "in Sirte or any other place."
The French magazine Paris-Match reported Thursday that the rebels nearly caught Gaddafi on Wednesday but he got away and is still somewhere in Tripoli. The report cited an unnamed "reliable source" as saying a cell of rebel and Arab intelligence services located a plain, modest house in central Tripoli where Gaddafi had spent at least one night.
The report said Libyan rebels then stormed the house, but Gaddafi had already left. It said there was some unidentified proof that Gaddafi had been there.
Britain previously provided a small number of military advisers — thought to be around 12 — to help organize Libya's rebel forces. France and Italy also sent similar troops to assist the anti-Gaddafi forces with training and logistics.
A Western diplomat, who spoke on condition of anonymity, said special forces from some Nato nations — operating outside the alliance's command structure — may now be engaged in the hunt for Gaddafi.
US aircraft accounted for most of the more than 20,200 sorties flown by Nato aircraft in the five-month war in Libya. The largest proportion were flights by American aerial tankers refueling allied strike planes, as well as AWACS and other surveillance aircraft.
European warplanes — mainly French and British — have flown the vast majority of the airstrike sorties, but US armed drones and some jets — such as those tasked with radar-supressing Wild Weasel missions — have also participated.
In Brussels, a Nato spokeswoman declined to comment, saying only that the alliance does not discuss intelligence matters. "Nato does not target specific individuals," spokeswoman Oana Lungescu said.
Asked about the concentration of airstrikes around Tripoli overnight, she said the situation in Libya remains dynamic and Nato continues to monitor it closely.
"There are still threats and attacks across the country," she said. "We continue to strike whenever and wherever necessary to complete our mission."
That mission, according to a UN mandate, is to protect civilians in Libya from attacks by Gaddafi's forces.