Well-armed Gaddafi forces were numerous and appeared to gain the upper hand, but were later forced to retreat.
Separately, the Netherlands confirmed three of its marines had been captured by pro-Gaddafi forces.
They had been helping to evacuate two European civilians when they were detained in the city of Sirte.
Col Gaddafi has warned he will "fight until the last man and woman".
In a televised speech on Wednesday, Col Gaddafi also said that thousands of Libyans would die if Western forces intervened.
Discussions continue at the UN about the idea of implementing a no-fly zone to stop pro-Gaddafi forces launching air attacks on rebel forces.
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