By Alexander Dziadosz
AJDABIYAH, Libya (Reuters) - Libyan rebels painted the roofs of their vehicles bright pink on Friday to avoid more friendly fire casualties after a NATO air strike killed five fighters.
The strike hit a rebel tank column as it advanced on the disputed oil port of Brega on Thursday, causing a confused insurgent retreat back toward Ajdabiyah, gateway to the uprising's stronghold in Benghazi.
NATO, which is enforcing a no-fly zone in Libya aimed at protecting civilians, on Friday acknowledged that its planes were probably responsible for the friendly fire incident, the second in a week.
Rebels heading west from Ajdabiyah toward the front against forces loyal to Muammar Gaddafi said the paint on their vehicle roofs was to avoid more friendly fire.
Another NATO strike last week killed 13 rebels, including ambulance staff, on the outskirts of Brega.
"Twice, they've hit us by accident now," grumbled Belgassim Awamy, a rebel volunteer near the western entrance of Ajdabiyah.
"NATO is an alliance against the Libyan people," said Alaa Senudry, another rebel standing nearby.
NATO says Gaddafi forces are sheltering near civilian areas, making it difficult to hit them effectively from the air.
Some rebels insisted Gaddafi aircraft had staged Thursday's attack, despite the fact that his air force has been grounded by the NATO planes.
"That was Muammar, it came from the south," said Wanis Boumarie, a former policeman turned rebel volunteer, when another rebel blamed the attack on NATO.
"NATO is extremely slow," he said, suggesting Gaddafi warplanes might have evaded the no-fly zone.
NATO has repeatedly denied rebel accusations that the pace of air strikes has reduced since the alliance took over from a coalition of the United States, France and Britain on March 31.
A group of rebels gathered on the western outskirts of Ajdabiyah later came under a bombardment which forced them back.
This correspondent heard 12 explosions, apparently from an artillery bombardment, and bursts of machine gun fire. There was no sign of an advance by Gaddafi forces.
A pick-up truck full of men with AK-47 assault rifles, sped into the Ajdabiyah hospital, carrying a wounded man they said had been hit about 18 km west of the town.
The bed of the pick-up truck was filled with blood-stained ammunition and bandages.
(Editing by Barry Moody)