Cairo: Some 10,000 Egyptians fleeing a violent revolt in Libya are crowded at the border between the two neighbours, a security source said on Tuesday, adding that Cairo had beefed up its frontier forces.

Two Egyptian military aircraft have meanwhile arrived in Tripoli to help evacuate Egyptians from the Libyan capital, the source told the media.

"The army has sent extra units to ensure security along the northern frontier with Libya at the Sallum border crossing and to allow Egyptians fleeing Libya to safely return," the source said.

Some 10,000 Egyptians are already at the border, waiting to cross, after 5,000 compatriots came over on Monday, she said, adding that a field hospital had been set up at Sallum to deal with anyone needing urgent medical care.

The dusty Bedouin town of Sallum is the first community on the Egyptian side of Mediterranean coastal road out of Libya.

Egypt on Monday confirmed the deaths of two of its nationals, cut down by machine-gun fire, while an Egyptian doctor at the border, citing witnesses, said 10 had been killed in coastal Tobruk, 150 kilometres (90 miles) away.

Foreign Minister Ahmed Abul Gheit said that, besides the two military aircraft already in Tripoli, Libya has given a green light for an additional flights - two military and two civilian operated by Egyptair.

Given that damage to the runway at Benghazi airport, he said, Egyptians in Libya's second city - a focal point of the uprising - "should stay inside to avoid the dangers of driving 500 kilometres (300 miles) of road to the border."

According to the Egyptian foreign ministry, around 1.5 million Egyptians work in Libya, representing a significant presence among Libya's own population of 6.3 million.

Libya is geographically bookended by Egypt to the east and Tunisia to the west - both Arab neighbours where longtime leaders stood down in the face of popular uprisings.

Egypt and Libya fought a brief border war in July 1977, but recent years have seen a marked degree of economic cooperation, including the joint development of their oil and gas industries.

With the situation in Libya in flux, the foreign ministry in Cairo has reminded the Libyan authorities 'of their duty to ensure the safety of Egyptian nationals and property'.

It took exception to Gaddafi's influential son Seif al-Islam for suggesting, on Libyan television in the early hours of Monday, that Egyptians might be among foreign elements stirring up unrest.

"Such talk puts in danger the lives of Egyptians living in Libya," said foreign minister Abul Gheit, who announced the formation of a working group to monitor developments there.

The doctor who reported the Tobruk deaths, Seif Abdel Latif said on Monday he was trying to head to Libya with an aid convoy, only to be stopped by Egyptian border guards who only allowed medical supplies and two doctors to proceed.

"We saw a group of Egyptians, who come from the (Nile Delta province of) Sharqiya, escaping Libya on board three buses, and they said that 10 Egyptians had been killed by machine-gun fire in Tobruk," he said.

They had been slain by 'armed gangs, mercenaries,' according to the witnesses, the doctor said.