MADRID, March 30, 2008 (AFP) - Police in Spain's northern Basque Country found fragments from a small explosion near a telecommunications antenna Sunday after a telephone warning by the separatist group ETA, regional officials said.

The blast caused minor damage and no injuries, the Basque interior ministry said in a statement.

Police experts had gone to the site near the Basque town of Azpeitia after a telephone warning in the name of ETA at around 11:00 a.m. (0900 GMT), the statement added. But the warning had not said when the blast would occur.

A spokesman for the interior ministry had earlier said police believed there had been two explosions at the site, but the ministry statement said closer inspection revealed only one.

'The damage was slight and affected the door of the enclosure and the interior,' the ministry's statement said. 'Experts from the Basque police force said it was a device with a timer of a type normally used by ETA.'

ETA is blamed for 822 deaths in its 40-year campaign for an independent Basque nation encompassing parts of northern Spain and southwestern France.

Last June, it called off a 15-month-old ceasfire, since when it has staged a number of attacks.

On March 7, suspected ETA gunmen killed a former Socialist councillor in the Basque region, two days before general elections.