NATO's airstrikes targeting an armed convoy in Sirte on Thursday likely contributed to former Libyan leader Muammar Gaddafi's capture, an official said on Friday.

"At the time of the strike, we did not know that Gaddafi was in the convoy. We later learned that Gaddafi was in the convoy. Therefore the strike likely contributed to his capture," the official told Xinhua.

"We targeted an armed convoy, which was a legitimate military target... NATO does not target individuals and Gaddafi was not the target of this operation," he said.

NATO said in a statement on Friday that its aircraft on Thursday struck 11 pro-Gaddafi military vehicles, which were part of a larger group of some 75 vehicles in Sirte.

"These armed vehicles were leaving Sirte at high speed and were attempting to force their way around the outskirts of the city," said the statement.

According to the statement, a NATO aircraft firstly destroyed only one vehicle, which disrupted the convoy and making many vehicles changing direction.

However, a group of some 20 vehichles continued "at great speed" to flee and were bombed by another NATO aircraft, leaving 10 of them destroyed, the statement said.