Paris Gare de l'Est train station has been evacuated after two suspected packages have been found, raising fears of another terrorist attack after last week's massacre in the French capital.
The incident at one of Paris' biggest train stations came after local police arrested a dozen people overnight.
Those arrested were suspected of providing "logistical support" to the Kouachi brothers, who killed 12 people at the headquarters of satirical magazine Charlie Hebdo, and Amedy Coulibaly, who shot dead a policewoman and four Jewish customers at a kosher supermarket.
The arrests were made in the region south of Paris including Montrouge, where the policewoman was killed.
Meanwhile, US secretary of state John Kerry has arrived in Paris for talks with French Foreign Minister Laurent Fabius and President Francois Hollande.
"It's good to be with you. We have a lot to talk about," Kerry said to Fabius.