MISRATA, Libya - Libyan rebels Monday broke out toward Tripoli from the opposition-held port of Misrata 140 miles to the east, cracking a government siege as fighters across the country mounted a resurgence in their four-month-old revolt against Moammar Gadhafi.

The rebels gained a diplomatic boost as well when the visiting the German foreign minister said the nascent opposition government was "the legitimate representative of the Libyan people." Guido Westerwelle was visiting Benghazi, the capital of the rebel-held east of the country, to open a liaison office and hand over medical supplies.

He stopped short of full diplomatic recognition of the Transitional National Council, as has the United States, awaiting the ouster of Moammar Gadhafi from his more than 40-year rule in the oil-rich North African country.

Germany has refused to participate in NATO airstrikes in Libya and withheld its support for the UN resolution that allowed the attacks.

What started as a peaceful uprising against Gadhafi has become a civil war, with poorly equipped and trained rebel fighters taking control of the eastern third of Libya and pockets of the west.

But the fighting had reached a stalemate until last week when NATO began the heaviest bombardment of Gadhafi forces since the alliance took control of the skies over Libya under a UN resolution to protect civilians from Gadhafi's wrath. NATO has been pounding Gadhafi military and government position with increasing vigor and the rebels are again on the move.

Gadhafi's power has been considerably degraded by the NATO attacks as well military and government defections.

In London, Libyan analysts reported Monday that Gadhafi had lost another close official who defected and fled the country.

Sassi Garada, one of the first men to join Gadhafi when he took power, left Libya through Tunisia, according to Noman Benotman, a Libyan analyst in London who was in contact with his friends and family. Guma el-Gamaty, U.K. organizer for Libya's interim council, also confirmed the defection.

There were initial reports that Garada fled to Britain, where he has several family members, but Benotman said Garada was in Switzerland.

British officials, who spoke on condition of anonymity to discuss immigration and security matters, said they could not confirm whether Garada was in the U.K. Swiss Foreign ministry spokeswoman Carole Waelti told AP the government was "not aware of the possible presence of Mr. Garada in Switzerland."

Garada reportedly passed up several military promotions over the years to stay out of the limelight and serve Gadhafi, said Benotman, who works as an analyst for the London-based Quilliam Foundation.

Garada is also from Libya's Berber minority, which has often fought the Arab majority to have their language and customs protected. Many Berbers occupy the Western mountains of Libya, where Garada had been in charge of trying to neutralize tensions, el-Gamaty said.

It is not known why Garada defected or when, but he is one in a growing list of senior officials who have fled the country, suggesting Gadhafi may be losing his grip on power.

Last month, Shukri Ghanem, the Libyan oil minister and head of the National Oil Co., crossed into neighboring Tunisia.

Others who have defected include Foreign Minister Moussa Koussa, one of Gadhafi's earliest supporters; Interior Minister Abdel-Fatah Younes; Justice Minister Mustafa Abdul-Jalil, and Ali Abdessalam Treki, a former UN General Assembly president. A number of ambassadors and other diplomats also have resigned.

In the major fighting near Misrata on Monday, an Associated Press photographer at the rebel front lines said they had pushed along the Mediterranean Sea to within 10 kilometres of Zlitan, the next city to the west of Misrata. A rebel commander said his forces, using arms seized from government weapons depots and fresh armaments shipped in from Benghazi, planned to have moved into Zlitan, by Tuesday.

Ali Terbelo, the rebel commander, said other opposition forces already were in Zlitan, trying to encircle Gadhafi troops. If the rebels take the city they would be within 135 kilometres of the eastern outskirts of Gadhafi's capital, Tripoli.

An AP reporter with rebel forces said shelling was intense Monday morning with rockets and artillery and mortar shells slamming into rebel lines west of Dafniya at a rate of about seven each minute. Dafniya is about 30 kilometres west of Misrata

Officials at Hikma Hospital in Misrata said government shelling had killed seven rebels and wounded 49 on Sunday. New casualty figures were not available but ambulances were rushing from the Dafniya line back into Misrata.

Rebels encountered a major setback, however, near the eastern oil town of Brega on Monday. Suleiman Rafathi, a doctor at the hospital in the town of Ajdabiya where the casualties were taken, said 23 rebels were killed and 26 wounded in a government ambush about 35 kilometres east of Brega.

The front lines between Brega and Ajdabiya have been relatively quiet in recent weeks, while fighting has raged in western Libya.

In other diplomatic developments, U.S. Secretary of State Hillary Rodham Clinton spoke again against the Libyan regime, telling the nations of Africa on Monday to sever links with Gadhafi despite his long support and patronage for many African leaders.

In a speech on Monday to diplomats at the African Union headquarters in Addis Ababa, the Ethiopian capital, Clinton said Africa should join most of the rest of the world in abandoning Gadhafi. She said the Libyan leader has lost all legitimacy to rule because of attacks on his own citizens.

She's urged all African leaders to demand that Gadhafi accept a cease-fire and then leave Libya.

In a lighter moment, the Gadhafi was shown on Libyan television playing chess with the visiting Russian head of the World Chess Federation. The federation is headed by the eccentric Kirsan Ilyumzhinov, who until last year was the leader of Russia's predominantly Buddhist republic of Kalmykia. He once claimed to have visited an alien spaceship.

The television report showed Gadhafi, dressed all in black and wearing dark sunglasses, playing chess Sunday evening with his Russian guest.

Russia's Interfax news agency quoted Ilyumzhinov as saying Gadhafi told him he has no intention of leaving Libya despite international pressure.

It was unclear where the chess game took place. Gadhafi's compound in the center of Tripoli has been under NATO bombardment and was hit again Sunday.

Gadhafi had not been seen in public since mid-May, and Ilyumzhinov told him how pleased he was to find him healthy and well.