UK: Airspace shut, planes grounded flying to and from UK amid network failure; French envoy to stay in Niger despite ultimatum, says Macron; France bans Muslim students from wearing abaya dress in state schools; US, Turkey hold largest military drills in seven years amid efforts to improve ties br br #UK #UKAirspace #UKAirspaceShut #NetworkFailure #UKFlightsbr ~PR.152~ED.194~HT.