Police in Paris halted traffic on a commuter train line for about an hour Thursday evening after the United States warned French officials of a possible bomb attack, police said.
Authorities found nothing suspicious and lifted the alert around 9:30 p.m. (3:30 p.m. ET).
The RER-A line was stopped and passengers were evacuated while officials conducted inspections of the rails and stations, authorities said.
Police headquarters in Paris said the CIA alerted it to the threat of a bomb attack directed at the underground train lines or the Metro subway system.
In Washington, an administration source said the U.S. government told the French government about a nonspecific but credible threat of a bomb attack.