By Youssef Boudlal and Matt Robinson
KIKLA/MISRATA, Libya, June 14 (Reuters) - Libyan rebels made fresh gains on the western front on Tuesday, pushing back forces loyal to leader Muammar Gaddafi in a string of clashes that took them closer to the capital Tripoli.
In the east, rebel forces sought to extend an advance begun on Sunday, setting their sights on the oil town of Brega in a bid to extend their control over the east of the country, epicentre of the four-month rebellion against Gaddafi's four-decade rule.
Rebels seized the town of Kikla, southwest of Tripoli on Tuesday, after government troops fell back, and pushed several kilometres (miles) west of their Misrata stronghold to the outskirts of government-controlled Zlitan, Reuters photographers said.
Pro-Gaddafi forces retreated about nine kilometres (five miles) from Kikla and rebels were setting up defensive positions, Reuters photographer Youssef Boudlal said.
In Brussels, a NATO spokesman said rebel forces were making steady gains in the west and the Berber highlands, and appeared to "control the ground from Wazin to Jadu and Zintan as well as the town of Yaffran."
The rebel advance to Kikla, some 150 km (90 miles) from Tripoli, came after weeks of relative deadlock between the rag-tag army and government forces, though air strikes by NATO have taken their toll on Gaddafi's better-equipped troops.
Nevertheless, rebels in the west said attacks on a Misrata oil refinery were causing them fuel supply problems. And a NATO leaflet drop warning of helicopter strikes prompted some rebels to retreat from their newly captured positions outside Zlitan.
"We came back (from Zlitan) because of the leaflets from NATO. I hope there is some coordination between the fighters and NATO. Gaddafi's forces are far away. Is it logical that NATO has no idea we took those positions?" Mohammed Genei, 31, local commander told Reuters. "NATO dropped the leaflets right on us."
A leaflet obtained by Reuters showed a picture of a helicopter and a burning tank.
"When you see these helicopters, it means it is already too late for you," it said in Arabic. "There is no place to hide. If you continue threatening civilians, you will be killed."
A NATO official said NATO did drop leaflets warning of the possibility of attack by attack helicopters, but said this was west of Misrata, and closer to Zlitan.
However, even without the threat of NATO attack, the rebels said they would not attack Zlitan, citing tribal sensitivities. Instead they would wait for the local inhabitants to rise up.
Despite the successes on the battlefield the rebels could struggle to maintain their momentum after a rocket attack on Monday badly damaged a refinery near Misrata port, potentially causing them serious fuel supply problems.
An engineer on site said it was unclear how long it would take to repair.
NATO reported skirmishes around Brega and Ajdabiyah but said the east of Libya was relatively quiet, but said there were reports of a rebel offensive on Zawiya, an important oil producing port 30 km (20 miles) west of Tripoli.
"This area appears to a hotspot for pro- and anti-Gaddafi clashes," NATO military spokesman Wing Commander Mike Bracken told a briefing in Brussels.
"NATO continues to focus intelligence gathering capabilities in this area to build a better understanding of events on the ground," he added. He did not elaborate.
NATO said it struck an armoured vehicle armed with anti-aircraft guns east of Tripoli on Tuesday as well as a multiple rocket launcher and another anti-aircraft system.
In a statement the alliance also said it struck an armed pickup truck, a tank, a multiple rocket launcher and an armoured vehicle in Misrata on Monday night.
"These types of equipment have been used to indiscriminately target the civilian population throughout Libya," the commander of the NATO mission, Lieutenant-General Charles Bouchard, said.
"NATO will maintain the pressure on the Gaddafi regime and continue to take action to protect civilians."
"VIOLATION OF SOVEREIGNTY"
The fighting east of Tripoli came during an apparent lull in NATO bombardment of the Libyan capital, a lull which continued through Tuesday, although state television reported the alliance had bombarded targets in Al Jufrah in the centre of the country.
NATO defence chiefs were due to meet in Belgrade on Tuesday to discuss the mission, after U.S. Defence Secretary Robert Gates accused some European allies of failing to pull their weight in a mission he feared could run out of steam.
Libyan troops fired Grad rockets over the border into Tunisia on Tuesday, witnesses said, in an assault likely to raise already high tensions between the nations.
The explosions, close to rebel territory along the border in Libya's Western Mountains, caused no damage or injuries.
The last time this happened, on May 17, Tunisia threatened to report Libya to the U.N. Security Council.
Fighting flared at the weekend in Zawiyah, 50 km (30 miles) west of the capital -- clashes the rebel leadership said were a sign the four-month-old conflict was shifting their way.
But a Zawiyah resident, who could only be identified as Mohamed, told Reuters by phone on Tuesday that it had since gone quiet, with neither side having advanced much.
"Things are now calm in Zawiyah. Gaddafi's forces are still in their place in town and on the main road," he said.
The main highway west from Tripoli to Tunisia, which had been closed because of the fighting, appeared to have re-opened.
A rebel spokesman in Zintan, in the rebel-held Western Mountains range southwest of Tripoli, said the town had been quiet on Monday after heavy bombardments on Sunday.
Gaddafi has said the rebels are criminals and al Qaeda militants. He has described the NATO military intervention as an act of colonial aggression aimed at grabbing Libya's oil.
Western governments say they believe it is only a matter of time before Gaddafi's 41-year rule ends under the weight of NATO military intervention, sanctions and defections.
NATO member Germany became the latest country to recognise the rebel council based in the second city of Benghazi as the legitimate representative of the Libyan people.
France, Qatar, Italy and the United Arab Emirates have already recognised the Transitional National Council.
"We share the same goal -- Libya without Gaddafi," German Foreign Minister Guido Westerwelle said in Benghazi.
Libya's foreign ministry in a statement condemned the visit as an "irresponsible step by the German state."
"The visit ...is a blatant violation of national sovereignty and ... international laws," it said, adding that Germany was "recognising an imaginary council that only represents itself."
Adding to diplomatic pressure on Gaddafi, U.S. Secretary of State Hillary Clinton urged African leaders to abandon him.
Gaddafi has styled himself the African "king of kings" and over the years won support from many African states in exchange for financial help and generous gifts.
"Your words and your actions could make the difference... (in ending this situation) ...and allowing the people of Libya to get to work ... rebuilding their country," Clinton told the African Union in the Ethiopian capital Addis Ababa.
(Additional reporting by Matt Robinson in Misrata, Souhail Karam in Rabat, Tarek Amara in Tunis, Nick Carey in Tripoli, Hamid Ould Ahmed in Algiers and David Brunnstrom in Brussels; Writing by Tim Cocks and John Irish; Editing by Jon Boyle)
