Police defused three makeshift bombs in a busy tourist resort and on a high-speed rail line in the French Basque country, officials said Friday.
More than 1,000 tourists were evacuated in the middle of the night from their holiday homes after firefighters received a telephone tip-off alerting them to a total of five explosive devices in the southwestern region.
Two were found in the Basque village of Arcangues, in a holiday resort and outside the tourism office, and a third on a TGV rail line near the Atlantic town of Ondres, at the northern edge of the Basque country.
Officials said all three devices had been easily defused, and that holidaymakers had been allowed to return to their accommodation Friday morning.
"The explosive devices turned out to be makeshift contraptions, of limited power and defective," the local prefecture in Pau said in a statement. "All the sites have been secured and reopened to the public."
Bomb disposal experts searched three other sites named by the anonymous caller, who gave the alert at around 4:00 am (0200 GMT), but uncovered no evidence of explosives.
The sites were a seafront casino in Biarritz, an exclusive hotel and restaurant run by star French chef Alain Ducasse in the Basque town of Biadarray and a holiday village in the town of Anglet.
"No suspect elements were found," said an official at the regional prefecture in Pau.
Officials earlier said the device planted on the rail line was thought to be a gas canister equipped with a detonator. No details were given of the other devices.
Rail traffic was cut along the southwestern Atlantic coast following the bomb alert, while the rail station in Bordeaux was shut for two hours to allow a safety inspection on a night train arriving from Paris.
Anti-terrorism police and gendarmes have opened a joint investigation, a police official said.
The scare comes after a French-based Basque separatist group warned in April that it planned a campaign of attacks in Spain and France to further its call for an independent Basque homeland.
The little-known group, whose name Irrintzi means "Shout" in Basque, has claimed half a dozen low-level attacks or attempted attacks since August 2007 in the Basque region of southwest France, targeting estate agents, tourist sites and a police station.
Police in France also regularly detain suspected members of Spain's armed separatist group ETA, which is blamed for the deaths of 823 people in a 40-year campaign of bombings and shootings to carve a Basque homeland out of northern Spain and southwestern France.
ETA, whose initials stand for Euskadi ta Askatasuna, or Basque Homeland and Freedom in the Basque language, is designated a terrorist organisation by the United States and the European Union.
In recent month it has been hit by a string of arrests of high-profile members, and seizures of weapons caches.