Three bombs exploded in northern Spain on Sunday _ including one outside a bank _ causing damage but no injuries, officials said. A caller earlier warned about the explosives, saying he was speaking on behalf of Basque separatists.

The first detonated without warning around 5 a.m. outside a bank in the northern town of Getxo, damaging a cash dispenser and breaking windows, according to a regional Interior Ministry official in Bilbao who did not give her name in line with government policy.

Five hours later, a caller warned fire officials in the Basque town of Muskiz that two bombs would explode in Laredo and Noja in the neighboring province of Cantabria.

A bomb exploded in the sand next to Laredo’s beach-front promenade at around 12:20 p.m., and a second device detonated in sand dunes on a Noja beach around 1 p.m., according to a spokesman for Cantabria’s regional Interior Ministry in Santander.

Laredo and Noja, with their long, sandy beaches, are popular summertime destinations. Getxo, near the Basque port of Bilbao, is home to many business leaders.

The armed Basque group ETA has been fighting for decades for an independent Basque homeland in northern Spain and western France. More than 800 people have died in Basque violence.

The group ended a self-imposed cease-fire in December 2006 with a deadly bombing at a parking lot at Madrid’s international airport.

Since then, ETA regularly has detonated small bombs, often after phoning in warnings.