Supporters of Libya's leader Muammar Gadhafi chant slogans in central Tripoli March 6, 2011. [Photo/Agencies]

RAS LANOUF, Libya - Libyan helicopter gunships fired on a rebel force advancing west toward the capital Tripoli along the country's Mediterranean coastline on Sunday and forces loyal to leader Muammar Gadhafi engaged in intense ground battles with the rival fighters.

The opposition force pushed out of the rebel-held eastern half of Libya late last week for the first time and have been cutting a path west toward Tripoli. On the way, they secured control of two important oil ports at Brega and Ras Lanouf and by Sunday, the rebels were advancing farther west when they were hit by the helicopter fire and confronted with ground forces.

Fierce ground battles were raging around the front line between two towns, Ras Lanouf and Bin Jawad, to the west. Associated Press reporters at the scene said Gadhafi loyalists retook Bin Jawad, about 160 km east of Gadhafi's hometown and stronghold of Sirte, which could prove to be a decisive battleground.

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In Tripoli, the city of 2 million that is most firmly in Gadhafi's grip, residents were awoken before dawn by the crackle of unusually heavy and sustained gunfire that lasted for at least two hours.

Libyan government forces have completely regained control of Zawiya, some 40 km west of Tripoli after two days of fighting, Undersecretary of Foreign Affairs Khalid Kilba told reporters on Saturday.

The official also confirmed that the government forces have been engaged in fighting with anti-government insurgents in Brega and Ras Lanuf.

British soldiers 'held'

A small British diplomatic team is in the Libyan city of Benghazi, British Defense Secretary Liam Fox said on Sunday, but he declined to comment on a report that Libyan rebels had captured a British special forces unit.

"I can confirm that a small British diplomatic team is in Benghazi. We are in touch with them, but it would be inappropriate for me to comment further on that for reasons I'm quite sure you understand," Fox told the BBC.

Despite repeated questions, Fox refused to say whether the group was in danger or was being held captive.

The Sunday Times reported that Libyan rebels had captured a British special forces unit in the east of the country after a secret diplomatic mission to make contact with opposition leaders backfired.

"We want to clearly understand what the dynamic is there because we want to be able to work with them to ensure the demise of the Gadhafi regime, to see a transition to greater stability in Libya and ultimately to more representative government," he said.

Fox ruled out the use of British military ground forces in Libya but said a no-fly zone remained a possibility.

Vigilant Algeria

The Algerian army has heavily deployed troops to guard the border with Libya, local daily el-Khabar newspaper reported on Sunday.

The paper said a military field medical unit has been sent to the border.

It said the army is planning to heavily monitor air traffic over Algerian cities near the borders to prevent weapon smuggling.

Meanwhile, a lot of foreigners fleeing from a turmoil in Libya have begun arriving in Algeria after reports that government forces started to guard exit routes to Tunisia and Egypt.

The UN High Commissioner for Refugees said it is seeing fewer people arriving at the nation's borders with Tunisia and Egypt.

AP-Reuters-Xinhua