The French Rafael fighter helping enforce a no-fly zone over Libya destroyed what was identified as a Libyan G-2/Galeb, which is a trainer aircraft. It happened near the coastal city of Misrata.
French Foreign Minister Alain Juppe says it could take days or even weeks to achieve the mission's goal of protecting citizens from Gadhafi's troops.
NATO ships patrolled the coast to block the flow of arms and mercenaries, while other coalition bombers truck artillery, arms depots and parked helicopters, officials said.
In Tripoli, Libyan deputy foreign minister Khaled Kaim said that the "military compound at Juffra" was among the targets hit before dawn. Juffra is one of at least two air bases deep in Libya's interior, on main routes that lead from neighboring countries in the Sahara region that have been suppliers of arms and fighters for the Gadhafi regime.
Benghazi rebels were seen waving the flags of Libya's past - the flag from before Moammar Gadhafi's rule. The U.S. says it's proof that the no-fly zone is working.
"I know that the nightly news cannot cover a humanitarian crisis that thankfully did not happen, but it is important to remember that many, many Libyans are safer today because the international community took action," said Secretary of State Hillary Rodham Clinton.
With Gadhafi reportedly looking for a way out, Clinton issued a challenge.
"Gadhafi has a decision to make, and the people around him each have decisions to make. The quickest way for him to end this is to actually serve the Libyan people by leaving," she said.
So far, the majority of attacks on Libya have been U.S.-led. Of 161 Tomahawks fired, 157 have been Americans. The other four were British.
President Barack Obama will meet with his national security team on Libya on Thursday. He has said the U.S. will reduce its involvement to a support role within days.
Republican leaders want Obama to explain the U.S. mission in Libya. They have sent a letter to the White House and are calling for congressional hearings.
The Associated Press contributed to this report.