NATO airstrikes targeted a technical school in Tripoli, Libyan state television reported Saturday, hours after leader
Moamer Gaddafi warned the Western military alliance that it will face "catastrophe" if the attacks continued, reported DPA.
State television cited a military spokesman as saying that technicians, engineers and students were in the school, but would provide no additional details.
Gaddafi on Friday threatened to attack Europe if NATO did not stop its airstrikes.
"We advise you to retreat before you face a catastrophe," Gaddafi said in a telephone message through state television, addressing his supporters who had gathered in Tripoli's Green Square, carrying photographs of him and green flags.
He vowed to stay on and called on his supporters to head unarmed towards the rebel-held cities of
Misurata and Brega.
Libya has repeatedly accused NATO of hitting civilian targets, claiming that more than 700 civilians have been killed since the airstrikes began in March.
NATO has recently intensified its attacks on Tripoli in a bid to increase pressure on Gaddafi.
It also stepped up its military pressure on Gaddafi's forces in western Libya, disrupting attempts to increase their attacks on civilians, the alliance said in a statement.
Since June 27, NATO's operations have resulted in the destruction of more than 50 military targets in the region between the Nafusa Mountains near the Libyan-Tunisian border to the city of Misurata.
The International Criminal Court has issued arrest warrants for Gaddafi, his son Saif al-Islam and his intelligence chief Abdullah al-Senussi for alleged crimes against humanity.
NATO marked 100 days of airstrikes on Libya on Monday. Its nearly 13,000 sorties have helped bolster the rebels, who have been trying to reach the capital, where Gaddafi remains in control.
The uprising to oust Gaddafi, who has been in power for 42 years, began in mid-February as protests turned into an armed conflict after the government's lethal crackdown on demonstrators.