Three people were lightly wounded early Sunday when a bomb exploded in northern Spain. The bomb went off at about 2:30 a.m. (0030 GMT) outside the offices of construction company Amenabar to the east of Zarautz, a seaside city 34 miles from the French border in the Basque Country, a regional Interior Ministry official told The Associated Press, on condition of anonymity in keeping with government rules. An hour earlier, road assistance service DYA had received an anonymous call warning of the bomb. Police were inspecting the area when the bomb exploded, the official said. The caller did not identify himself as a member of the armed Basque group ETA, although the incident is similar to earlier bomb explosions attributed to the group.