Nato said on Friday its aircraft probably killed Libyan rebels in a "friendly fire" incident on Thursday near the oil port of Brega.
Rebels said on Thursday that five of their fighters were killed in a Nato strike on a column of tanks moving towards Brega from Ajdabiyah further east. The aircraft apparently believed the tanks belonged to forces loyal to Muammar Gaddafi.
British Rear Admiral Russell Harding, deputy commander of Nato operations in Libya, told a news briefing: "It would appear that two of our strikes may have resulted in deaths of (rebel) forces. The incident took place in the east of Brega where fighting had gone back and forth on the road to Ajdabiyah."