EAST OF BREGA/BENGHAZI, Libya (Reuters) - A NATO-led air strike killed 13 Libyan rebels, a rebel spokesman said on Saturday, but their leaders called for continued raids on Muammar Gaddafi's forces despite the "regrettable incident."
In the rebel capital of Benghazi the anti-Gaddafi council also named a "crisis team," including the former Libyan interior minister as the armed forces chief of staff, to run parts of the country it holds in its struggle to topple Gaddafi.
The 13 fighters died on Friday night in an increasingly chaotic battle over the oil town of Brega with Gaddafi's troops, who have reversed a rebel advance on the coastal road linking their eastern stronghold with western Libya.
Hundreds of mostly young, inexperienced volunteers were seen fleeing east from Brega toward the town of Ajdabiyah after coming under heavy mortar and machinegun fire.
A contingent of more experienced and better organized rebel units initially held their ground in Brega, but with most journalists forced east, it was unclear whether they had remained inside the town or had pulled back into the desert.
A Reuters correspondent visiting the scene of the air strike saw at least four burned-out vehicles including an ambulance by the side of the road near the eastern entrance to the town.
Men prayed at freshly dug graves covered by the rebel red, black and green flag nearby.
Most blamed a Tripoli agent for drawing the "friendly fire." "Some of Gaddafi's forces sneaked in among the rebels and fired anti-aircraft guns in the air," said rebel fighter Mustafa Ali Omar. "After that the NATO forces came and bombed them."
But some gave a different account. "The rebels shot up in the air and the alliance came and bombed them. We are the ones who made the mistake," said a fighter who did not give his name.
The strike killed 13 rebels and wounded seven, rebel spokesman Hafiz Ghoga said, calling it a "regrettable incident."
"The military leadership is working on ways to prevent a recurrence," he told reporters in Benghazi.
Another rebel spokesman, Mustafa Gheriani, told Reuters the leadership still wanted and needed allied air strikes. "You have to look at the big picture. Mistakes will happen. We are trying to get rid of Gaddafi and there will be casualties, although of course it does not make us happy."
In Brussels a spokeswoman for NATO, which this week assumed command of the military operation launched on March 19, declined to say whether its forces were involved in the Brega incident.
"We are looking into the report," said spokeswoman Oana Lungescu. "However, if someone fires at our aircraft, they have the right to protect themselves."
NATO has conducted 363 sorties since taking over command of the Libya operations on March 31, and about 150 were intended as strike missions but NATO has not confirmed hitting any targets.
Fighting raged around Brega's university early on Saturday, rebels said. But at the eastern gate of the town, volunteers known as the "shebab," or youth, streamed away in cars after coming under heavy fire from Gaddafi's forces.
The volunteers have frequently fled under fire, raising questions about whether the rebels can make any headway against Gaddafi's better-equipped and better-trained forces without greater Western military involvement.
Brega is one of a string of oil towns along the coast that have been taken and retaken by each side after the U.N. mandated intervention which was intended to protect civilians in Libya.
Rebels have been trying to marshal their rag-tag units into a more disciplined force after their advance along about 200 km (125 miles) of coast west from Brega was repulsed and turned into a rapid retreat this week.
The stalled campaign has left rebel-held areas in western Libya, notably the city of Misrata, stranded and facing intense attacks from Gaddafi's forces.
One Benghazi-based rebel said food supplies were acutely low in Misrata. "There are severe food shortages and we call on humanitarian organisations to help," said the rebel called Sami, who said he was in regular contact with a Misrata resident.
"The city has been under siege for a month and a half. The main shortages are fruit and vegetables because those come from the south and the southern entrance to the city is controlled by Gaddafi's men."
A British-based doctor who arrived in Misrata three days ago on a humanitarian mission said 160 people, mostly civilians, were killed in fighting in the town over the last seven days.
The doctor, who gave his name as Ramadan, said he had no official figures for the total death toll since the fighting started six weeks ago. "But every week between 100 or 140 people are reported killed -- multiply this by six and our estimates are 600 to 1,000 deaths since the fighting started," he said.
State-controlled Libyan television said coalition forces bombarded "civilian and military locations" in western Libya late on Friday. The strikes were in the towns of Khoms, between the capital Tripoli and Misrata, and Arrujban, in the southwest.
Showing footage of two men receiving medical treatment while lying in hospital beds, it said, "This is the result of attacks by crusader aggressors in Khoms."
In Benghazi, the rebel council named its "crisis team" on Saturday to administer parts of the country it controls.
Omar Hariri is in charge of the military department, with General Abdel Fattah Younes al Abidi, a long serving officer in Gaddafi's armed forces, as his chief of staff.
Younes, a former Libyan interior minister, changed sides at the start of the uprising in mid-February but is distrusted by many in the rebel camp because of his past ties to Gaddafi.
(Additional reporting by Angus MacSwan in Benghazi, Tom Pfeiffer in Cairo, Maria Golovnina in Tripoli; Joseph Nasr in Berlin, Justyna Pawlak in Brussels, writing by David Stamp; editing by Matthew Jones)
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