NATO warplanes dashed into the Libyan capital Tripoli at mid-day on Friday, pounding a target in the south of the city and sending a thick cloud of black smoke rising high into the air.

A series of explosions rumbled across other parts of the city as fighter jets could by heard flying overhead. Fire engines raced through the streets, sirens blaring.

It wasn’t clear what was hit or whether there were casualties. Friday is the main day of rest in Libya, with many people off work.

NATO has been ramping up the pressure on Muammar Qadhafi’s regime. Though most airstrikes happen under cover of darkness, daytime raids have grown more frequent.

Friday’s raids follow a barrage that struck multiple targets late Thursday night.

The fresh strikes blasted the capital as renewed diplomatic efforts to halt Libya’s civil war appeared to be gaining momentum, though there are no signs a breakthrough is imminent.

On Thursday, Russia’s envoy to Libya met with senior government leaders in Tripoli, but not Gadhafi himself, in an effort to stop the fighting.

Last week, the envoy Mikhail Margelov visited the Libyan rebel stronghold of Benghazi and said that Gadhafi has lost his legitimacy. However, the envoy also said NATO airstrikes are not a solution to Libya’s violent stalemate.

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