ROME — Pope Francis doubled down Saturday on his efforts to quash the old Latin Mass, forbidding the celebration of some sacraments according to the ancient rite in his latest salvo against conservatives and traditionalists.

The Vatican’s liturgy office issued a document that clarified some questions that arose after Francis in July reimposed restrictions on celebrating the old Latin Mass that Pope Benedict XVI had relaxed in 2007.

Francis said then that he was reversing his predecessor because Benedict’s reform had become a source of division in the church and been exploited by Catholics opposed to the Second Vatican Council, the 1960s meetings that modernized the church and its liturgy.

The Vatican repeated that rationale on Saturday, saying the clarifications and new restrictions were necessary to preserve the unity of the church and its sacraments.

“As pastors we must not lend ourselves to sterile polemics, capable only of creating division, in which the ritual itself is often exploited by ideological viewpoints,” said the prefect of the Vatican’s liturgy office, Archbishop Arthur Roche, in an introductory note to the world’s bishops.

Francis’s crackdown on the old Mass has outraged his conservative critics, many of whom have gone so far to accuse him of heresy and watering down Catholic doctrine with his focus on the environment, social justice and migrants. Francis says he preaches the Gospel and what Jesus taught, and has defended the restrictions by saying they actually reflect Benedict’s original goal while curbing the way his 2007 concession had been exploited for ideological ends.

His July law required individual bishops to approve celebrations of the old Mass, also called the Tridentine Mass, and required newly ordained priests to receive explicit permission to celebrate it from their bishops, in consultation with the Vatican. Saturday’s decree makes clear the Vatican must explicitly authorize new priests to celebrate the rite.

In addition, the new document Saturday imposes restrictions targeting the sacramental life of the church.

It forbids using the ancient ritual for the sacraments of Confirmation and ordaining new priests, and will make it exceedingly difficult for traditionalists to access the sacraments of Baptism, Marriage and Anointing of the Sick according to the old rite.

This de facto prohibition arises because these sacraments can only be celebrated in so-called personal parishes that were already in existence and dedicated to traditionalist communities. There are exceedingly few of these parishes around the world, and Francis barred the creation of new ones.

“Roche Christmas Massacre,” tweeted Rorate Caeli, a traditionalist blog that has been critical of Francis and his crackdown on the Tridentine rite.

“Benedict XVI had brought peace to the church. An end to the liturgical wars,” the group said in a follow-up message to The Associated Press. “The current pope has chosen to reignite them. There is no logical reason for that. Just an underlying desire for division and violence.”

Francis agreed to the publication of the document, which was signed by Roche, who is prefect of the Vatican’s liturgy office.

It was written in the form of questions and answers, including some that get into minute details that make clear the Vatican’s effort to minimize the spread of the old Mass: Parishes may not, for example, publicize the celebration of the old liturgy in parish bulletins or allow them to be celebrated at the same time as the so-called New Order Mass.

In a clear bid to dissuade seminarians from even learning the old rite, the new instruction urges seminary teachers to lead their charges “to an understanding and experience of the richness of the liturgical reform called for by the Second Vatican Council.”

If a priest who is authorized to celebrate the old rite gets sick at the last minute, he can’t be substituted with one who doesn’t have prior approval. In addition, priests may not celebrate an old rite Mass and the New Order one on the same day.

Joseph Shaw, head of the Latin Mass Society of England and Wales, said the restrictions mean celebration of the old Latin Mass “will become extremely difficult” and the sacraments even more so.

“This would drastically reduce the number of celebrations, and cause great pastoral harm,” he said in an email.