ROME (Reuters) - At least 40 civilians have been killed in air strikes by Western forces on Tripoli, the top Vatican official in the Libyan capital told a Catholic news agency on Thursday, quoting witnesses.

"The so-called humanitarian raids have killed dozens of civilian victims in some neighborhoods of Tripoli," said Giovanni Innocenzo Martinelli, the Apostolic Vicar of Tripoli.

"I have collected several witness accounts from reliable people. In particular, in the Buslim neighborhood, due to the bombardments, a civilian building collapsed, causing the death of 40 people," he told Fides, the news agency of the Vatican missionary arm.

Libyan officials have taken foreign reporters to the sites of what they say were the aftermath of Western air strikes on Tripoli but evidence of civilian casualties has been inconclusive.

Western powers say they have no confirmed evidence of civilian casualties from air strikes, which they have carried out under a U.N. mandate to protect civilians caught in conflict between Libyan leader Muammar Gaddafi's forces and rebels........