A French court on Wednesday handed a four-year jail term to Emmanuel Abayisenga - a Rwandan - for starting a fire that severely damaged a Gothic cathedral in the city of Nantes in 2020.

According to France 24, Abayisenga, 42,, is also facing legal action for a separate incident in which he allegedly killed a priest in western France in 2021.

The court ruled that Abayisenga was not mentally sound at the time of the fire at the Cathedral of Saint Peter and Saint Paul when it handed down the sentence.

The court also banned Abayisenga from bearing weapons and staying in the western Loire-Atlantique region, where Nantes is located, for five years.

Abayisenga, who arrived in France in 2012 and had been a volunteer for the local diocese, had admitted causing the blaze at the start of the hearing.

He said he had entered the cathedral to pray but then "lost control" after passing by a location in the building where he suffered a violent attack in 2018.

Speaking through an interpreter, he said he regretted what happened and asked for forgiveness.

Abayisenga has a history of unsuccessful asylum claims and received an order to leave France in 2019, which was said to have deeply troubled him.

Prosecutor Veronique Wester-Ouisse said the defendant set fire to the cathedral knowingly due to "huge anger and a feeling of revenge linked to his administrative situation".

Firefighters were able to contain the blaze quickly and save the main structure, but its famed 17th-century organ, which had survived the French revolution and bombardment during World War II, was destroyed.

Also lost were priceless artefacts, paintings and stained-glass windows that contained remnants of 16th-century glass.

The cathedral's owners estimated the damage at more than 40 million euros ($43 million).

The blaze in Nantes came 15 months after the devastating fire at the Notre-Dame cathedral in Paris, which raised questions about the security risks for other historic churches across France.