The outgoing head of the Arab League Amr Moussa has voiced concerns about NATO's bombing campaign in Libya in an interview with a British newspaper on Wednesday.

The veteran Egyptian diplomat, who played a key role in securing Arab support for the UN Security Council Resolution that authorised NATO air strikes, told the Guardian the bombing mission may not be working.

"When I see children being killed, I must have misgivings. That's why I warned about the risk of civilian casualties," he said.

NATO has been forced to defend the credibility of its air war after the alliance admitted firing a rogue missile that the Libyan regime says killed nine civilians, including children, in Tripoli.

The Libyan regime has claimed another 15 civilians were killed in an attack on the western Tripoli suburb of Sorman on Monday, but NATO insists it hit a legitimate military target.

In the interview, Mussa called for a ceasefire and said talks on a political settlement should start even while Muammar Gaddafi remains in power.

Mussa made clear the military campaign would not produce a breakthrough.

"You can't have a decisive ending. Now is the time to do whatever we can to reach a political solution," he said.

"That has to start with a genuine ceasefire under international supervision. Until the ceasefire, Gaddafi would remain in office.

"Then there would be a move to a transitional period... to reach an understanding about the future of Libya." Asked whether that meant a halt to the NATO air strikes, he said: "A ceasefire is a ceasefire."