London: Pope Francis has ordered a Belgian Catholic charity to stop offering euthanasia in its psychiatric hospitals.

In May, the Brothers of Charity group announced it would allow doctors to perform euthanasia at its 15 psychiatric hospitals in Belgium, one of only two countries, along with the Netherlands, where doctors are legally allowed to kill people with mental health problems, at their request.

To qualify, people must be in a state of "unbearable suffering" and at least three doctors, including one psychiatrist, must be consulted.

The charity said in a statement that euthanasia would only be performed if there were "no reasonable treatment alternatives" and that such requests would be considered with "the greatest caution".

"We respect the freedom of doctors to carry out euthanasia or not," the group said, noting that this freedom was "guaranteed by law."

The Vatican press office said this week that the pope had asked the Belgians not to perform euthanasia.

The Catholic Church opposes euthanasia and the Holy See has begun investigating the decision to allow the procedure, which was made by the group's lay board of directors.

The Belgian charity's administrative headquarters in Rome issued a statement in May, arguing that allowing euthanasia "goes against the basic principles" of the Catholic Church.

"This is the very first time a Christian organisation states that euthanasia is an ordinary medical practice that falls under the physician's therapeutic freedom," wrote the charity's superior general, Rene Stockman, who delivered the request from Pope Francis via two letters.

"This is disloyal, outrageous and unacceptable." Mattias De Vriendt, a spokesman for the Belgium charity, said it had received the Vatican's request but had not yet responded.

"We will take our time in the next few weeks to evaluate these letters," de Vriendt said. He said the charity's hospitals had received requests from patients seeking euthanasia recently but could not say whether any procedures had been performed.

The vast majority of patients seeking euthanasia in Belgium have a fatal illness like cancer or a degenerative disease. While the number of people euthanized for psychiatric reasons accounts for only about 3 percent of Belgium's yearly 4,000 euthanasia deaths, there has been a threefold increase in the past decade.

Critics have previously raised concerns about Belgium's liberal approach to euthanasia while advocates say that people with mental health illnesses should be granted the same autonomy as those with physical diseases.

The American Psychiatric Association says that doctors should not prescribe any methods to people who are not terminally ill to help them die.