Defence officials said French aircraft destroyed four tanks in strikes southwest of the rebel-held city of Benghazi.
Earlier Nicolas Sarkozy said aircraft were over Libya preventing attacks on Benghazi after the leaders met in Paris to discuss a military response to the civil war in Libya.
He said the aim of intervention was not regime change but to “allow the Libyan people to choose their own destiny”.
“We are determined to take all necessary action, including military consistent with UN Security Council resolution 1973 to ensure compliance with all its requirements, ” Mr Sarkozy said.
“We are protecting the population from the murderous madness of the regime.”