|Rebels have made gains in western Libya amid NATO air raids in the region that commenced late last week [Reuters]
NATO has denied the Libyan government's charge that it intentionally carried out air raids to aid rebel advances, saying it is sticking to UN mandate to protect civilian lives.
Wing Commander Mike Bracken, an alliance spokesman in Naples, Italy, said on Friday that NATO was "not involved in the ground battles".
However, he acknowledged that NATO was tracking the fighting between Libyan opposition fighters and forces loyal to Muammar Gaddafi, the country's long-time leader.
Khaled Kaim, Libya's deputy foreign minister, accused NATO on Thursday of intensifying its bombing campaign and backing foreign mercenaries to lay the groundwork for an advance by rebels trying to topple Gaddafi's government.
In an interview with the Associated Press news agency, Kaim said increased bombings in recent days represented the "final phase" of NATO's air campaign.
But he said the push will fail and that civilians would be the ones to pay the price.
Kaim said NATO targeted police checkpoints in the Nafusa Mountains southwest of Tripoli before a rebel advance towards the village of al-Qawalish, which rebel fighters said they seized on Wednesday.
A fuel depot in the key eastern oil town of Brega was also destroyed, Kaim said.
NATO insisted it hit equipment used to refuel government military vehicles.
"The aim of these attacks is to help the rebels to advance. But I assure you, it will be another failure for them," Kaim said.
Rebels wrested the town of al-Qawalish in western Libya from Gaddafi forces after a roughly six-hour battle on Wednesday.
The two sides fought mostly at a distance, using heavy artillery, and black plumes of smoke could be seen rising from al-Qawalish in the afternoon, Al Jazeera's Jonah Hull reported.
Kaim further said his government has evidence that Colombian mercenaries funded by the West and its Arab allies have joined the rebel fighters in the rebel-held western city of Misurata.
NATO denied the allegations and said "there's nothing to indicate this allegation might be true".
Oana Lungescu, a NATO spokesperson, said: "But what we have seen are repeated consistent and credible reports that Gaddafi's forces have been using mercenaries, not just now or in recent months but for years and decades."
|Al Jazeera's Jonah Hull reports on the capture of al-Qawalish by rebel forces
NATO began air raids against Libya in March. The coalition and its Arab allies are operating under a UN mandate to protect civilians.
Libyan officials showed on Monday journalists assault rifles and ammunition they claimed had been shipped to rebels by Gulf Arab state of Qatar.
NATO announced late last week it had begun ramping up its raids on military targets in the western part of Libya. It said it was targeting government forces in cities and along "major lines of communication".
Meanwhile, Italy has decided to cut back its participation in NATO's campaign by removing an aircraft carrier from the region and pulling thousands of troops home.
Silvio Berlusconi, the Italian prime minister, has said he had always been against the war but had his "hands tied" once the UN authorised a no-fly zone to protect Libyan civilians.
US House vote
The West's Libya campaign got a boost as the US House of Representatives turned back an effort on Thursday to prohibit funds for the US military operation against Libya.
This was a win for President Barack Obama in the ongoing constitutional showdown with Congress over war powers.
The vote was 229-199 against the measure that would have barred funds for US participation in the NATO-led mission in Libya.
Opponents argue that Obama violated the 1973 War Powers Resolution that requires a president to seek congressional approval within 60 days of the first military strikes.
But Obama informed congress last month that such assent was unnecessary because the limited US role does not rise to full-blown hostilities.
The House voted overwhelmingly last month to deny Obama the authority to continue the mission, a largely symbolic vote. But they stopped short of cutting off funds.
Since NATO took command of the Libya operation in early April, the US role has largely been limited to support efforts such as intelligence, surveillance and electronic warfare.
The US has launched air raids and drone attacks, flying more than 3,400 sorties.
Earlier, Ban Ki-moon, the UN secretary-general, spoke to Al-Baghdadi al-Mahmoudi, the Libyan prime minister, over phone on Wednesday about the "urgent need" to end the fighting and "work out a transition that could bring peace to all Libyans".
A brief provided by Ban's office said Abdelilah al-Khatib, the UN special envoy for Libya, will be visiting Tripoli soon for urgent consultations.