Two small bombs claimed by the Basque separatist group ETA exploded Wednesday along a Spanish section of the Tour de France, ETA's first attack since ending a 15-month ceasefire in June.
No one was hurt and the incident failed to disrupt the race.
The devices, placed in plastic food containers, went off on both sides of the road in the town of Belagua just across the border with France, a regional government official told AFP.
The explosives went off just after a caravan of Tour-related publicity vehicles went by but before the Tour riders passed through as the three-week race briefly entered the northern Spanish region of Navarra.
The blasts, which occurred 30 minutes apart, only kicked up dirt.
"There was no damage," the official said, adding that the devices were placed 50 metres and four metres from the road, respectively.
Highway assistance authorities received a telephone warning two hours before the blasts from a caller claiming to represent ETA.
Police found no further bombs. The two devices that went off each used between 0.5 and one kilogram (2.2 pounds) of explosives, possibly ammonal, the interior ministry said in a statement.
Ammonal is an industrial explosive typically used for quarrying or mining.
ETA, which has killed more than 800 people in four decades of armed struggle to achieve independence for the Basque region of Spain and the Basque part of southwestern France, has threatened the Tour de France in the past.
The armed group declared a "permanent" ceasefire in March 2006 but grew frustrated with the ensuing peace process with the Socialist government of Prime Minister Jose Luis Rodriguez Zapatero and set off a car bomb at Madrid's airport in December that killed two men.
The government has adopted a hard line against ETA since the group formally declared the end of its ceasefire last month.
At least 15 members of ETA have been arrested since the end of the truce.
The latest arrest, that of Pablo Aperribai Bediaga who has been on the run since fleeing Spain in 2005, took place in Lammemezan, a town in southeastern France, just hours before the blasts occurred.
Bediaga, 37, was detained while he attempted to steal a car, Spanish Interior Minister Alfredo Perez Rubalcaba said.
Spanish authorities had issued an arrest warrant for Bediaga who is believed to have helped gather information about high profile ETA targets.
He was unarmed and was not carrying identity papers at the time of his arrest.
Spanish authorities have thwarted at least two plans by the armed group to carry out attacks since the end of the ceasefire.
In June, police found a car loaded with 100 kilograms (220 pounds) of explosives in southwestern Spain just across the Portuguese border which authorities believe ETA planned to use to target tourist targets during the peak summer season.
Earlier this month authorities detained an alleged ETA member in the northern Spanish coastal city of Santander who had plans to carry out an attack using a car bomb.
ETA, whose name stands for Basque Homeland and Freedom, is classified as a terrorist group by the European Union and the United States.
© AFP 2007