(CNN) -- Hours after being released from custody, the daughter of a prominent Bahraini human rights activist was feared to be detained again early Sunday, her family said.
Zainab al-Khawaja called her mother Sunday morning, telling her in a brief conversation that she was at a Manama police station and asking for a lawyer to be sent there, the woman's husband, Wafi Almajed, told CNN around 2:30 a.m. Sunday (7:30 p.m. ET Saturday).
The call was the first her family had heard from her in hours since she went to the military hospital where her father, Abdulhadi al-Khawaja, is receiving care while he is on a prolonged hunger strike. Abdulhadi al-Khawaja is protesting the life sentence he received for his role in the anti-government unrest that continues to embroil his country. Sunday marks the 60th day of his hunger strike.
The Bahrain Center for Human Rights -- a group Abdulhadi al-Khawaja founded -- said the man had recently called his family, saying he had been mistreated by guards and hospital staff. According to the group, he'd threatened his guards that he would stop drinking water, in addition to continuing his hunger strike, unless his treatment improved.
Zainab al-Khawaja went to the military hospital Saturday, to try to see her father, the rights group said. Her attempted visit was her second in three days and came just hours after she was released from custody for entering a restricted area in her first attempt Thursday.
Her first attempt came after seeing a picture of her father with no shirt -- looking thin and frail since his detention. Zainab al-Khawaja said she ran to the Interior Ministry complex where he was then being held and called out his name.
The Interior Ministry said she was arrested Thursday night for being in a restricted area "in which standing is prohibited." The ministry also said she "attacked an on-duty public employee."
She was released Saturday.
Mohammed Al Jishi, lawyer for both father and daughter, expressed concerns that Abdulhadi al-Khawaja could soon die.
However, Bahrain government spokesman Abdul-Aziz al Khalifa told CNN Saturday that al-Khawaja was receiving "the utmost care that is available" and was seen "very recently" by international human rights organizations.
"Mr. al-Khawaja is in stable care. He has been provided the best medical care," al Khalifa said, adding that the hunger striker has been observed around the clock by three doctors -- one, Danish -- for the past three weeks. Al-Khawaja lived in Denmark and holds Danish citizenship.
His family learned Friday that, on that same day, al-Khawaja was being moved to a military hospital because his condition was deteriorating, Al Jishi said.
Al Khalifa said al-Khawaja's appeal is scheduled for April 23 and he will get his day in court then.
Meanwhile, Bahrain's foreign minister said he has received a written message from his Danish counterpart requesting a transfer for Abdulhadi al-Khawaja to Denmark.
Bahraini authorities said they were examining the request.
Al-Khawaja was arrested last April for his role in anti-government demonstrations in February and March. In June, he and seven other Shiite opposition activists were found guilty of plotting to overthrow the country's Sunni royal family.
The Interior Ministry's general inspector said that "all policies and procedures of the prison facilities in Bahrain meet international human rights standards, and all detainees have consistent and reliable access to professional medical care," according to a statement from Maj. Gen. Tariq H. Al Hasan, a spokesman for the ministry.
On March 30, the government reported that Abdulhadi al-Khawaja had low blood pressure and was taken to Bahrain Defense Force Hospital, where he was treated and returned to Jau Prison the following day.
Records showed that al-Khawaja had lost about 10 kilograms (22 pounds) and had a low hemoglobin level, though not critically low, the government said. He was also reportedly taking fluids, mineral supplements, glucose and juice on a daily basis.
Demonstrators and Bahraini authorities have continued to clash in recent months, with the opposition accusing the government of using heavy-handed tactics.