A fake bomb near Paris held up rail traffic to northern France and London today unsettling Europe's already jittery financial markets exactly a week after the devastating train bombings in Madrid.
The "bomb" turned out to be an empty oxygen canister.
Separately, British police said they had closed off part of a domestic rail line in southern England near the Channel Tunnel link to France and arrested a man under anti-terrorism laws.
French authorities said police were told by a telephone caller of a suspicious package on rail tracks north of Paris.
"It was one big joke," said a local government spokeswoman in the Val d'Oise region just north of Paris. "The bomb disposal experts went to check it. It was empty."
A spokesman for the Eurostar passenger service that links Britain to continental Europe through the Channel Tunnel said there had been some delays on trains in and out of Paris.
It was a high profile example of the delays and disruptions being caused on rail and urban transport links across Europe by tightened security checks in the wake of the bombings in the Spanish capital that killed 201 people. Spain has arrested suspected Islamist militants it believes were behind the attack.
A spokeswoman for British police in Kent said of the incident on their side of the Tunnel: "A section of the line was closed. One man was arrested under the terrorism laws and he is helping police with their inquiries."
She said a 35-year-old man was under arrest but the incident seemed less serious than it first seemed: "It is certainly looking not as frightening as it was three hours ago," she said.
The dollar, which has suffered over renewed fear of terror attacks in the United States after the Madrid bombings, slid in currency markets after the news of the Eurostar alert. Stock markets were shaken also.