Violent clashes erupted between far-right groups, local residents and North African migrants in a town in southeastern Spain late on Saturday following an attack on an elderly man by unknown assailants earlier in the week.

Five people were hurt and one was arrested during the unrest in Torre-Pacheco, local officials told Reuters, in one of the worst such episodes in the country in recent decades. The town was quieter on Sunday, but government sources said more arrests were expected.

Videos posted on social media showed men dressed in clothes bearing far-right symbols and migrants carrying Moroccan flags hurling objects at each other in Saturday night’s violence, which followed several days of lower intensity unrest.

Tensions flared up between local residents and migrants after the elderly man was attacked in the street on Wednesday, causing injuries from which he is recovering at home. The reasons behind the assault are unclear and no one has been arrested.

The central government’s representative in the area, Mariola Guevara, told Spanish public TV the attack was being investigated.