Spain's Interior Ministry is blaming an outlawed separatist group for a bomb explosion outside a town hall in the northwestern region of Galicia.

Ministry delegate for the region Samuel Juarez said all signs indicated the explosion Wednesday outside the town hall of Baralla was the work of Galician Resistance, a small but violent group that seeks independence for the region.

The blast occurred shortly before 5 a.m. It caused substantial damage to the building and to nearby houses. No one was hurt.

No group has claimed responsibility for the blast and no warning call was made to authorities.

Juarez said people face trial next week accused of being members of the group. A similar bomb blast a year ago outside another town hall was also blamed on the Galician Resistance.