PARIS, Nov 2 (Reuters) - French aid worker Sophie Petronin, freed a year ago after four years in the hands of jihadist militants in northern Mali, is back in Mali and missing again, French daily Liberation reported on Tuesday. The paper reported that 76-year old Petronin - who ran a charity for malnourished and orphaned children when she was kidnapped near the desert city of Gao in late 2016 - had discreetly returned to Mali in April. Liberation said the director general of Mali"s gendarmerie police force had sent an internal note asking police to look for her and to bring her back to the capital Bamako. The Malian gendarmerie did not respond to a request for comment.