A judicial source and a spokesman for the Spanish city of Algeciras said authorities are investigating what they say is a possible "terrorist" incident, after a man stabbed several people in two churches in the southern Spanish city, killing at least one person.

A city spokesman said that the man attacked clerics in two different churches, San Isidro and Nuestra Señora de la Palma, about 300 meters apart, after eight o'clock on Wednesday evening in downtown Algeciras.

A source in the Madrid Supreme Court said that the investigation is underway into the incident as a terrorist.

Police said the attacker was arrested.

A police source released footage showing two officers leading a man wearing a tracksuit in handcuffs through a police station.

The police did not disclose his name or nationality.

A spokesman for the city of Algeciras said that the man who was killed was Diego Palencia, a clergyman in the church of Nuestra Señora de la Palma, and that Antonio Rodriguez - an honorary priest in the diocese of San Isidro - was among the injured, and he is in serious condition.

El Mundo newspaper reported that 4 people were injured in the attack.