"There were RPGs...which shows there were forces exploiting this. They are remnants of the (former) regime," he said. The news conference was broadcast on Al Jazeera television.
He suggested that the attackers could have been acting in revenge for the extradition from Mauritania this month of Gaddafi's former intelligence chief Abdullah al-Senoussi.
Gaddafi was ousted by rebel forces backed by NATO air power in August 2011 and was killed in October after months as a fugitive.