A Catholic bishop has written to schools to warn them against the use of yoga during class time and said that it is "not of Christian origin".

A spokesman for Bishop Alphonsus Cullinan, of the Waterford and Lismore diocese, confirmed that primary schools in the diocese under the patronage of the Catholic Church had received the letter, which also asked teachers to pray the rosary with their pupils.

Last year, Bishop Cullinan said that he is establishing a "delivery ministry" of exorcists to deal with evil spirits and also warned people against the use of Reiki and new age healing because they could be channeling "the wrong spirit".

His letter to schools, dated 10 October and which has been published on the Waterford News and Star's website, wished school principals, teachers and other staff well for the new school year.

"I have been asked by several people to say a word on yoga and mindfulness," Bishop Cullinan continued.

"My question is, 'will they bring us closer to Christ or replace him?' Yoga is not of Christian origin and is not suitable for our parish school setting and especially not during religious education time.

"Regarding mindfulness, in a sense it has been practised in the Christian tradition since the beginning, but Christian mindfulness is not mindlessness, but is meditation based on Christ, emptying the mind of everything unnecessary so that we become aware of the presence and love of Christ."

He quoted a homily delivered in 2015, in which Pope Francis told listeners that practices like yoga are not capable of opening people's hearts to God.

"You can take a million courses in spirituality, a million courses in yoga, Zen and all these things, but all of this will never be able to give you freedom," he quoted the Pope as saying.

Bishop Cullinan pointed out in his letter that October is the month of the rosary.

"I encourage you to pray the rosary and help the children to spend time with Jesus in adoration or in quiet meditation in the classroom," he said.

Last year, Bishop Cullinan revealed that he was in the process of establishing a "delivery ministry" of exorcists in his diocese, in response to several requests and reports he said he had received from people about "what they believe to be evil forces".

He also warned people against getting involved in Reiki or new age healing, "because if you're opening yourself up to a spirit and someone is channeling a spirit, they could be channeling the wrong spirit".

The bishop said last year that the brother of a Reiki master had told him that the master had seen "a vision of Satan" while working on somebody and was "scared out of his wits, dropped the Reiki and went back to the church".

He said that he had received nine requests in the last few years from people who wanted the services of an exorcist.

Bishop Cullinan's spokesman said earlier this year that "progress" was being made in forming the delivery team.