TEHRAN, Iran: Jailed Nobel Peace Prize laureate Narges Mohammadi was in critical condition in a cardiac care unit in ​northwestern Iran.

She had been ‌brought from prison to a hospital two days earlier, a foundation run by her family said.

Narges Mohammadi's blood pressure is still fluctuating dangerously, and doctors are only trying to keep her stable using oxygen, her foundation said.

She was moved from prison to a hospital in Zanjan late last week after her health suddenly became much worse. The foundation said she fainted twice and had a serious heart problem.

Mohammadi, who is in her 50s, won the Nobel Peace Prize while in prison for her work supporting women's rights and ending the death penalty in Iran. Her family said she may have had a heart attack in late March.

The foundation said she can only get proper treatment if she is moved to her own medical team in Tehran.

In February, the foundation said she was given a new prison sentence of seven and a half years, just weeks before the U.S.-Israel conflict with Iran began. At that time, the Nobel committee asked Iran to release her immediately.

Mohammadi's brother, Hamidreza ​Mohammadi, said she urgently needs special medical treatment for a serious heart problem that could be life-threatening.

He said she was having severe headaches, nausea, and chest pain, and that the family was most worried about her heart. Speaking from his home in Norway, he explained that the hospital where she is currently being treated cannot give her the care she needs.

He added that experts believe her life is in danger and that she needs at least one month away from prison conditions to recover properly. She should be treated by her own doctors, who have handled her case before and understand her condition well.

Both her family and the Norwegian Nobel Committee have asked Iranian authorities to move her to her medical team in Tehran for proper treatment.

She was arrested in December after criticizing the death of lawyer Khosrow Alikordi. A prosecutor, Hasan Hematifar, said she made controversial comments at a memorial event for Alikordi.