The Vatican has excommunicated 10 nuns from northern Spain after a months-long standoff over a property dispute and amid claims they belonged to a sect, it emerged Saturday.

"It was the sisters themselves who expressed their free and personal decision to abandon the Catholic Church," said a statement from the Archbishop of Burgos's office.

It issued the statement after the nuns failed to turn up for a meeting to discuss their position before a church tribunal.

The nuns excommunicated were among 16 Poor Clare sisters living in a 15th-century convent in the small northern town of Belorado near Burgos. The other six -- the eldest in the group -- have been spared excommunication as they are considered vulnerable.

On Friday, they had confirmed their "irreversible" desire to leave the Church following a dispute during which the Vatican blocked their attempt to buy another convent.

The stand-off began when the sisters accused the Vatican of "doctrinal chaos" and "contradictions" in positions on faith matters in a May 13 letter published on social media.

It was signed by the order's Mother Superior, Sister Isabel de la Trinidad, who said they were being "persecuted" for trying to purchase another convent in the northern Basque region.

The nuns say they see themselves as under the jurisdiction of excommunicated priest Pablo de Rojas Sanchez-Franco, known for his ultraconservative views.

He heads the Devout Union of the Apostle Saint Paul, a religious group regarded as heretics by the Catholic Church. Sanchez-Franco presents himself as a bishop, appearing in public in episcopal robes.

A 'false bishop'

The Vatican tasked the Archbishop of Burgos, Mario Iceta, who in 2019 excommunicated Sanchez-Franco, with approaching the sisters to bring them round and stop them from break away.

He also had to obtain the keys to their convent, which the Church says it owns.

The Church had given the rebel nuns until Friday to appear before an ecclesiastical tribunal to confirm their decision to split.

They had warned that this could mean excommunication -- a move that would deprive them of certain sacraments such as confession. But the nuns did not turn up for the tribunal.

Instead, they said in a statement Friday that they had sent a fax to the archbishop's office confirming "we have made known our unanimous and irreversible wish" to leave the Church.

They insisted their decision was "the fruit of mature, meditative and conscious reflection, which has been validated by all" the nuns of the community.

They were acting "freely and voluntarily" but stressing they did not recognise the tribunal, the statement added.

Saturday the Church in Spain responded: "On June 22, the Archbishop of Burgos, legal representative of the monastery of Belorado ... transmitted the decree declaring excommunication ... of the 10 sisters who caused a schism."

Theologian Luis Santamaria, founder of the Ibero-American Network for the Study of Sects, stated: "Excommunication is the most serious sanction measure in canon law."

He added: "In the specific case of the Poor Clares of Belorado, they can no longer be considered Catholic nuns and it is normal that they abandon a monastery where they no longer belong.

Santamaria dubbed Pablo de Rojas a "false bishop", leading "a sect" which "imitates traditional Catholicism and declares itself to be the depositary of the true Christian faith," thereby engaging in "disinformation, emotional pressure and lies".