The two, Dr Ainun Nahar Rita and chemical engineer Nurun Nahar Mita, have been leading an extremely confined and secluded life, being engrossed in religious practice and supernatural beliefs at their paternal house at Block-9, Section-6, Mirpur.

Their strange lifestyle caused a stir for the last several days after a team of the Bangladesh Society for the Enforcement of Human Rights (BSEHR) managed to convince the sisters and enter the house with the cooperation of Pallabi police and took them to a clinic for immediate treatment.

They were reduced to bone and skin, with younger one seriously ill, caused by lack of proper food and care in isolation.

"The incident is nothing ghostly or mysterious. This is just a case of serious mental disease caused by a multi-factorial situation," said psychiatrist Dr Mohit Kamal, who is attending to them.

Of the two, younger sister Mita has shown enough symptoms of schizophrenia while the state of the elder one shows a shared or induced delusional disorder, he said at a press conference organised by the BSEHR at the National Press Club.

The psychiatrist said one isolates oneself from the society and social life the way the two sisters have done only when one is schizophrenic.

He also said mental breakdown, suspicion, sense of insecurity and various social pressures might have caused their serious mental disorder.

Citing the WHO survey, Dr Mohit said that one percent of the population in Bangladesh suffer from serious mental diseases while 10 percent suffer from minor mental disorders.

Medicine specialist Dr Khaza Nazimuddin, a member of the medical board formed to treat the two sisters, said doctors are facing circumstantial problems in providing life-saving treatment to the sisters as they are behaving in a non-cooperative manner.

They even do not cooperate with the doctors in carrying out diagnostic tests and they refuse to be shifted to a suitable clinic or hospital, he added.

Their eldest sister Kamurn Nahar Hena, who was present at the press conference, said the death of their father Sharfuddin Ahmed Bhuyian in 1982 and their maternal uncle Shamsur Rahman Molla in 1990 left them in a state of helplessness.

She said that soon after her marriage in 1984, her two sisters started to dislike her visits to their paternal house. Gradually, the two sisters and their mother have isolated themselves from everyone and everything, she added.

When their mother Rowshan Ara Begum died in 2003, the two did not inform anybody and tried to bury her on the house premises, Hena said.

Ainun Nahar Rita obtained her MBBS degree from Salimullah Medical College in 1988 and joined the government service in 1991 but resigned in 1996.

Nurun Nahar Mita, who graduated from the Bangladesh University of Engineering and Technology (Buet) in 1992, served at the Sylhet Gas Field in 1994, Gas Infrastructure Development Project in 1996 and Buet's Petroleum Engineering Department in 1997.

Executive director of the BSEHR advocate Elina Khan was present at the press conference.