An attack on Tripoli by Libyan anti-government forces in recent days exposed Muammar Gaddafi's military to heavy NATO bombing but the rebels' push was not coordinated with the alliance, a NATO official said on Monday.
The official told Reuters the rebel offensive has forced Gaddafi to deploy more heavy equipment to defend his holdouts in Tripoli and other parts of Libya, allowing NATO to target his facilities with more precision.
The rebels captured most of the Libyan capital on Sunday in the culmination of an offensive that has brought Gaddafi to the brink of defeat.
They had been supported by NATO air strikes since the end of March, when the Western military alliance began fulfilling a United Nations mandate to protect civilians during the six-month Libyan civil war. NATO said there was no direct coordination.
"There is a misconception that NATO was working with the rebels in this most recent push towards Tripoli," the official said.
"What happened was the push by the opposition forced Gaddafi's heavy equipment to come into the open, equipment that he had been hiding ... When they (government forces) lost ground they used heavy equipment to shell villages they had lost."
NATO took advantage of new targets, he said, to bolster its efforts to eliminate artillery and facilities that threatened civilians in Libya.
"It was NATO reacting to a change in the battlefield in the last two, three days, so you saw a spike in the number of air strikes. "It wasn't NATO leading."
Since late March, NATO has targeted thousands of Gaddafi's military assets such as command centres, missile launchers, radars, tanks and other vehicles. On Sunday, its aircraft made 46 sorties aiming to identify and hit potential targets, hitting nearly 20 targets in the Tripoli area.
Early on during NATO's involvement in Libya, the rebels had frequently accused the alliance of not giving them enough fire power support to break a stalemate between them and Gaddafi that had dragged on for weeks.
But the alliance had been constrained, in part by a mandate that called specifically for protecting the population -- not aiming for regime change. That made for political difficulties in some NATO allies in trying to meet rebel demands for an escalation of air strikes.
There were also resource and strategy constraints. NATO argued it had run out of purely military targets that are easy to hit without endangering civilians early in its air campaign.
Experts had also said it would have been difficult for NATO to step up its campaign, given U.S. determination to keep to a back seat and limited European resources with military powers Britain and France engaged heavily in Afghanistan.
Signs that Western capitals were getting cold feet about continuing the NATO campaign had emerged in recent weeks as the conflict dragged on, although stepping away from Libya would have been embarrassing to the West.
The NATO official said the alliance's current Libya mandate, which expires on Sept. 27, was all but set to be extended, if necessary.
"NATO has always said it was committed to seeing this through," he said. "There is no reason to think we wouldn't extend the mission."