French city Lyon briefly evacuates metro on bomb alert

LYON, France (Reuters) - The southeastern French city of Lyon temporarily shut and evacuated its underground railway system due to a bomb alert, local officials and the city's transport operator said.

The metro was later reopened and traffic returned to normal after security experts carried out checks, the operator said.

France is on high alert and has stepped up army patrols of public buildings and transport networks as Islamist militant groups have threatened revenge attacks for France's military campaign against al Qaeda-linked rebels in Mali.

(Reporting by Catherine Lagrange; Writing by Leigh Thomas; Editing by Catherine Bremer and Kevin Liffey)