The government spokesman slammed as a "cowardly terrorist act which cannot be justified" an attack on an estate of a veteran comrade of leader Muammar Gaddafi.
NATO, reversing an initial denial, acknowledged its warplanes hit Sorman but insisted the target was military.
A statement said a precision air strike was launched against a "high-level" command and control node in the Sorman area early today.
"This strike will greatly degrade Gaddafi regime forces' ability to carry on their barbaric assault against the Libyan people," said Canadian Lieutenant General Charles Bouchard, commander of NATO operations in Libya.
"Wherever Gaddafi tries to hide his command and control facilities, we will find them and destroy them." A NATO official said the alliance was aware of regime allegations that 15 people, including three children, were killed but had no way of verifying them.
Another official had said earlier the alliance had not conducted any air strikes in the Sorman area, 70 kilometres (45 miles) from Tripoli.
Escorted there by authorities, journalists saw damaged buildings on the sprawling estate of Khuwildi Hemidi, who served on the Revolution Command Council Kadhafi created when he seized power in 1969.