BBC NEWS | Europe | CIA warns France of bomb threat

"Several Paris rail stations were evacuated on Thursday after the CIA warned of a possible bomb attack.
Police said the CIA had told the French authorities of an anonymous message they had received warning of a possible attack between 1830 and 1930 GMT. "

It figures: I have to read the BBC to find out why there were so many policemen guarding the train stations on my way home from work.