Huge explosions have rocked the Libyan capital, Tripoli, during a series of air strikes by low-flying Nato jets.
Some of the blasts appeared to strike close to the compound of Libyan leader Col Muammar Gaddafi.
The attacks came as diplomatic pressure mounts on Col Gaddafi to step down.
The head of the African Union Panel for Libya, Mauritanian President Mohamed Ould Abdel Aziz, said his departure had become necessary to end the conflict.
Russia and China, meanwhile, despatched for the first time top diplomats to the rebel stronghold of Benghazi in an attempt to mediate an end to the four-month-long conflict.
"We have come to Benghazi to facilitate dialogue between the two camps," Russia's Africa envoy, Mikhail Margelov, said.
At the same time, Libya's Foreign Minister Abdul-Ati al-Obeidi flew to Beijing for talks in what analysts describe as an attempt to regain diplomatic support on the international stage.
Whatever happens, there will be a negotiated solution
Mohamed Ould Abdel Aziz
Mohamed Ould Abdel Aziz Head of the AU Panel for Libya
On the military front, Nato carried out rare daytime strikes on Tripoli, including a wave of attacks on military barracks near Col Gaddafi's residence. The explosions shook the ground and smoke billowed into the air.
Libyan government spokesman Moussa Ibrahim condemned the strikes.
"Instead of talking to us, they are bombing us. They are going mad. They are losing their heads," Mr Ibrahim said.
Russia's President Dmitry Medvedev recently said the Libyan leader had lost legitimacy and should step down - echoing the views of most Western powers.