By Mohammed Abbas
RAS LANUF, Libya (Reuters) - Government troops seeking to dislodge rebels from Libya's coast advanced on an oil town on Monday amid accelerating humanitarian efforts to prevent worsening civilian suffering and a mass refugee exodus.
The United Nations and the European Union are dispatching fact-finding missions to the north African nation, where reports by residents of attacks on civilians by security forces have triggered a war crimes probe and provoked global outrage.
The resilience of Muammar Gaddafi's troops in the face of protests which started in mid-February and their ability to counter-attack on a key coastal road has raised the prospect that this OPEC nation is heading for months of bloodshed.
"It's clear the government feels a sense of momentum on its side," said military analyst Shashank Joshi, an associate fellow at Britain's Royal United Services Institute.
"Government forces have more mobility than the rebels thanks to airlift and a decent amount of road transport.
"That's blunted by the fact that we are seeing extremely poor fighting skills by government forces, and reasonably competent fighting by the rebels."
The rebels have called for U.N.-backed air strikes against what they say are African mercenaries used by Gaddafi to suppress an uprising against his 41-year-old strongman rule.
The government says it is fighting against al Qaeda terrorists and maintains that its security forces have targeted only armed individuals attacking state institutions and depots.
Witnesses said government forces advanced on the rebel-held oil port of Ras Lanuf 600 km (400 miles) east of Tripoli in a counter-attack that forced residents to flee and rebels to hide their weapons in the desert.
The army was moving down the strategic Mediterranean coastal road east of the recaptured town of Bin Jawad, heading toward Ras Lanuf which is about 60 km (40 miles) away and which has a major oil complex, witnesses told Reuters.
"I went to Bin Jawad and about 20 km (13 miles) beforehand I saw Gaddafi forces, a large truck and army vehicles, and a fighter jet, they were coming slowly in this direction," Ahmed al-Araibi, a driver, told Reuters.
"I saw army trucks ahead, I was about 20 km away (from Bin Jawad)," said Khalifa Saad, another driver. While another witness said there were several trucks heading to Ras Lanuf.
Residents of Ras Lanuf, fearing assault by army forces, were leaving in cars laden with belongings on Monday and rebels said they had moved weapons into the desert for safekeeping.
As the rival combatants prepared to resume battle, the authorities launched an appeal to the rebels in the east for dialogue, in the clearest overture yet to their opponents.
Jadallah Azous Al-Talhi, a Libyan prime minister in the 1980s who is originally from eastern Libya, appeared on state television reading an address to elders in Benghazi.
He asked them to "give a chance to national dialogue to resolve this crisis, to help stop the bloodshed, and not give a chance to foreigners to come and capture our country again."
In the West, after what residents said was fierce fighting on Sunday with artillery, rockets and mortar bombs, rebel forces announced they had fought off Gaddafi's forces in the towns of Zawiyah, to the immediate west of Tripoli, and Misrata to the east.
If rebel soldiers were able to push their fitful advance westwards, Misrata could be a stepping stone to reaching the capital, Tripoli, Gaddafi's principal powerbase.
As the conflict escalated in Libya, U.S. crude oil rose to a 2-1/2-year high on Monday.
U.S. crude for April rose as much as $1.90 to $106.32 a barrel, the highest price since September 2008, heightening concerns that high energy prices may derail the global economic recovery. The U.S. government reiterated that it could tap its strategic oil reserves to safeguard economic growth.
The U.N. chief on Sunday demanded an end to "indiscriminate" attacks against civilians in Libya and warned Tripoli anyone who violates international law will be brought to justice.
U.N. Secretary-General Ban Ki-moon spoke with Libyan Foreign Minister Musa Kusa on Sunday and told him that Tripoli must "uphold their responsibility to protect the country's citizens and to heed the Libyan people's legitimate aspirations."
Ban appointed former Foreign Minister of Jordan, Abdelilah Al-Khatib, as a special envoy to Libya "to undertake urgent consultations with the authorities in Tripoli and in the region on the immediate humanitarian situation," Ban's press office said.
Gaddafi, in a French newspaper interview released on Sunday, said he was embroiled in a fight against terrorism and expressed dismay at the absence of support from abroad.
"I am surprised that nobody understands that this is a fight against terrorism," the longtime autocrat of the North African oil-producing state told the Journal du Dimanche in excerpts of an interview due to be published later on Sunday.
"Our security services cooperate. We have helped you a lot these past few years. So why is it that when we are in a fight against terrorism here in Libya no one helps us in return?"
British Foreign Secretary William Hague said on Sunday that what he called a UK diplomatic team that had been seized in the eastern city of Benghazi had now left Libya.
The Sunday Times earlier reported a British Special Air Service (SAS) unit had been captured during a secret diplomatic mission to make contact with opposition leaders backfired.
"They (the rebel army) did capture some British special forces. They could not ascertain if they were friends or foes. For our safety we are holding them and we expect this situation to be resolved soon," a rebel source in Benghazi said earlier.
RUSI analyst Joshi said the episode might offer a propaganda boost for Gaddafi, who was likely to portray it as evidence that the revolt was foreign-inspired rather than indigenous.
(Additional reporting by Michael Georgy in Tripoli, Alexander Dziadosz in Ajdabiya, Mohammed Abbas in Ras Lanuf, Stefano Ambrogi in London, Nick Vinocur in Paris and Tom Pfeiffer in Benghazi; Writing by William Maclean; editing by Giles Elgood)