Spanish police have raided the home of a Moroccan man arrested the previous night after allegedly killing a man with a machete and severely injuring a priest in attacks on two Catholic churches in the southern city of Algeciras.

Police are still investigating the motive of the assault, but a National Court judge is investigating it as a possible act of terrorism.

The suspect is believed to have acted alone.

Officers searched the as-yet unnamed suspect’s home to “determine the nature, terrorist or otherwise”, of the alleged crime, Spanish interior minister Fernando Grande-Marlaska said.

The suspect is a Moroccan citizen with no prior criminal record “either in Spain or any other country”, the Interior Ministry said.

Mr Grande-Marlaska added that investigators do not think anyone else was involved.

The suspect had been under a deportation order since June last year due to his unauthorised migrant status in Spain.

The attacks have shaken the city, located near the southern tip of Spain across a bay from Gibraltar.

Witnesses said that in the second attack a machete-wielding assailant jumped on the altar of a church before chasing a wounded man into a city square and killing him.

The ministry said the dead man was a sacristan, an individual who prepares Mass, at the Church of Nuestra Senora de La Palma, while the priest was wounded earlier at the San Isidro church.

The Algeciras town hall identified the sacristan as Diego Valencia and the wounded priest as Antonio Rodríguez.

The parish priest for Nuestra Senora de La Palma, the Rev Juan Jose Marina, told Spanish media he thinks he was the attacker’s intended target.

“In the same way that he sought out the priest at San Isidro and no-one else, the same thing happened here,” Mr Marina said.

“If I had been here, I would be dead.”

A fellow sacristan who served with Mr Valencia at the church, Manolo Gonzalez, said the attacker climbed on the altar and Mr Valencia came out “and asked to know what was going on”.

Candles and flowers adorned the two small churches with whitewashed walls on Thursday.

Flags were flown at half-mast in Algeciras, and a minute’s silence was observed.

Algeciras is a multicultural port city and the first point of arrival for many boats from North Africa, putting it at the centre of Spanish debates on irregular migration.

The Islamic Commission of Spain, which represents Muslims in the country, condemned the “abominable, murderous and heartless act” in “a sacred space for our Catholic brothers in Algeciras”.

The violent acts at the churches may inflame social tensions stoked in an election year by the far-right Vox party, which is vying to win more seats in local and national governments, as well as to form governing coalitions with the centre-right Popular Party.

Vox’s leader, Santiago Abascal, linked the attack to his party’s platform of cracking down on unauthorised immigration.

Vox, the third largest party in Spain’s parliament, also presents itself as the protector of Spain’s Catholic heritage in a time when active church membership is waning.

“He had an order of expulsion,” Mr Abascal wrote on Twitter.

“How many more like him could there be in Spain?”

But the regional president of southern Andalusia, Juanma Moreno of the Popular Party, said Algeciras has residents from 129 countries and had never suffered a similar attack.

“Nobody can (use this) to make generic statements about an ethnic or religious group,” Mr Moreno said.

The secretary general of the Spanish Episcopal Conference, an organisation of Spain’s Catholic bishops, appealed for unity.

“We cannot demonise any group,” Cesar Garcia said, according to Spanish news agency EFE.

“We cannot let ourselves be easily provoked, we cannot add fuel on the fire, we cannot lapse into demagogy and we cannot identify terrorism with any religion.”