A heavy sandstorm in Ajdabiya limited the effects of the army's air power, but four shells fell six kilometres west of rebels’ position, according to opposition fighters.
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Air strikes targeted military buildings in Ajdabiya, according to rebel leaders, who also claim that some insurgents are still holding out in Brega, 80 kilometres to the west, but that they are undergoing intense artillery and naval attacks. The Libyan army claimed Brega had been captured on Sunday.
Dozens of civilians are evacuating the town on light trucks, heading northeast for Benghazi.
Overall rebel military commander General Abdel Fatah Yunis, who resigned as Kadhafi's interior minister soon after the uprising began in mid-February, said Sunday that Ajdabiya was "a vital city" and key to his defence plan.
The rebels have been pushed back at least 200 kilometres by Kadhafi’s forces in recent days under heavy shelling and air attacks.
Group of Eight countries met in Paris on Monday to discuss Libya.
Meanwhile, Turkey has reiterated its opposition to Nato intervention in Libya, warning it would trigger dangerous consequences.
"Military intervention by Nato in Libya or any other country would be totally counter-productive," the Anatolia news agency quoted Prime Minister Recep Tayyip Erdogan as saying.