Nato fighter jets struck the harbour in Tripoli bombing runs overnight, damaging five coastguard boats and a warship, the Libyan government said today.
In Brussels, Nato confirmed that its warplanes targeted the vessels and accused Libya of using its ships in the escalating conflict, including attempts to mine the harbour in Misrata.
Rebels trying to end the nearly 40-year rule of Libyan leader Colonel Muammar Gaddafi have been struggling to hold the Western city of Misrata against repeated attacks by forces loyal to Gaddafi.
Mohammed Rashid, general manager of the Tripoli port, said that the coastguard boats were used to patrol Libyan waters for immigrant boats trying to make it to Europe and for search-and-rescue activities.
The port official said some damage was done to the port, but that it was minimal. A government official later said he feared the Nato strike would discourage ships from using the Tripoli port, reducing imports and driving up the cost of basic goods for Libyans.
In a tour given to reporters at a distance from the area, a warship could be seen on fire, with flames and plumes of smoke rising the from stricken vessel.
Nato said it acted because the Gaddafi regime was employing more ships in its campaign against rebel fighters.
"Given the escalating use of naval assets, Nato had no choice but to take decisive action to protect the civilian population of Libya and Nato forces at sea," said Rear Adm. Russell Harding, deputy commander of the Nato operation.
"Nato has constantly adapted to the rapidly changing and dynamic situation in Libya and at sea," he said in a statement.
Nato is operating under a UN mandate to maintain a no-fly zone over Libya and to prevent attacks on the civilian population.
The Western coalition has stepped up its airstrikes in Tripoli in an apparent attempt to weaken Gaddafi's chief stronghold, the Libyan capital, and potentially target the leader himself. The Gaddafi family compound, Bab al-Aziziya, has been targeted several times.
Also, a Nato strike early today hit a police academy in the Tripoli neighbourhood of Tajoura, a government official said.
The airstrikes came a day after Gaddafi's forces rocketed the strongholds of rebel fighters - the strategic mountain heights south-west of the Libyan capital, rebels said.
The two sides appeared to be fighting for control of the two highways to the north and south of the Nafusa mountain range, which slices across the desert south of Tripoli to the western border with Tunisia.
Rebels, in particular, have used the road, bringing in supplies for camps to train fighters for what they hope will be a future push on the capital. Gaddafi forces have shelled rebel camps and cities in the region in an effort to take the high ground.