The imams were part of a peace mission that had convened in the town, Moussa Ibrahim, a government spokesman, claimed as state television showed images of casualties.
A Nato spokesman said there was no information about the claim, but that its air offensive around key Libyan cities and towns had significantly affected Col Muammar Gaddafi's forces.
Analysis of targets attacked by the alliance shows that there has been a switch in recent days from assisting the rebels to bombing "command and control" and other targets in Tripoli.
Franco Frattini, Italy's foreign minister, said he had information that Col Gaddafi had been injured in a Nato strike. Mr Frattini said Giovanni Martinelli, the Roman Catholic bishop in Tripoli, said the Libyan leader had left Tripoli after being injured in an air strike. "I tend to give credence to the comment of the Bishop of Tripoli, Monsignor Martinelli, who has been in close contact over recent weeks, when he told us that Gaddafi is very probably outside Tripoli and is probably also wounded. We don't know where or how," Mr Frattini said.
Mr Ibrahim dismissed the report. "It's nonsense," he said. "The leader is in good spirits. He is leading the country day by day. He hasn't been harmed at all."
And in an audio message broadcast on state TV last night, Col Gaddafi said: "I want to tell you that your bombing will not reach me because millions of Libyans bear me in their heart."
In the first three days of this week, according to Nato figures, alliance jets struck 24 "key targets" in and around Tripoli, compared with just eight in the whole of the previous week.[Ron: 24 targets bombed in Tripoli? HOW were those targets killing or threatening harm to civilians?].
Targets since Monday have included seven "command and control" facilities [Ron: Interesting terminology but WHAT DOES IT MEAN IN FACT?] in Tripoli, compared with just three over the previous 10 days.
On Thursday morning, hours after Col Gaddafi appeared on state TV for the first time in 12 days, Nato struck his heavily-fortified [Ron: WHAT does "heavily fortified" mean in this context?! Is that term used in order to justify bombing such places?] Tripoli leadership compound, Bab al-Aziziya.
In a sign of Gaddafi's nervousness about being targeted, his TV appearance was filmed in a ground-floor room at Tripoli's Rixos hotel, where about 50 foreign journalists are staying.
Staff at the Rixos said there was an underground tunnel from the hotel to Bab al-Aziziya, which is about half a mile away. On a rare visit to the compound, which is sealed off from the city by four rings of 15ft blast walls, journalists were shown a bomb crater in what was clearly the roof of a bunker. A black void was visible below, as well as the remains of a reinforced concrete structure. A government spokesman insisted it was a sewage facility, but other officials later admitted this was untrue.[Ron: Sooo... what is the implication?! Was this structure threatening to kill civilians? and if so, how?]
The layout of tunnels in the area is known to Nato since most were built by Western companies. Similar tunnels were discovered last month beneath Col Gaddafi's summer palace in the rebel-controlled city of al-Bayda, with bedrooms, bathrooms, kitchens and even a sauna 30 feet beneath the ground.[Ron: A sauna!!! How decadent!!! Well that justifies bombing Tripoli and trying to kill Colonel Gaddafi, the leader of a sovereign nation doesn't it????].