(CNN) -- Human rights groups urged Iran to stop alleged abuses of 17 political prisoners who have been on hunger strike since the end of July to protest deteriorating conditions at Tehran's notorious Evin prison.
The 17 are in Ward 350 at Evin, and were detained in the aftermath of the disputed 2009 presidential election, according to Human Rights Watch. At least five of the prisoners are members of the media, said the Committee to Protect Journalists. Some are prominent human rights activists and student leaders.
"Throwing these prisoners into solitary confinement instead of responding to their legitimate concerns only causes them further harm," said a statement from Joe Stork, the deputy Middle East director at Human Rights Watch.
"They need to be reintegrated back into the general population, get the care they need, and be allowed to contact their loved ones," Stork said.
Iranian opposition leader Mehdi Karrubi said he feared for the health of the prisoners, who were transferred to solitary confinement after they complained about inhumane prison conditions. They launched a hunger strike July 26.
"One should sit down and listen to their concerns," he said. "I urge my children to end their hunger strike and the authorities must also pay attention and follow up on their demands, because a hunger strike has very harmful consequences."
Karrubi's comments were reported by the reformist Etemad-e Melli, the official newspaper of Karrubi's party, and posted on the Facebook page of opposition leader Mir Hossein Moussavi.
Karrubi met with some of the families of the journalists and said he was "deeply distressed by the country's situation and the confrontations that are being taken place against journalists and the families of [political] prisoners," according to SahamNews, the official website for the Etemad Melli party.
Families have said several of the prisoners are suffering health problems; some require care for diabetes, multiple sclerosis and heart disease, according to Human Rights Watch.
Hada Ghaemi of the International Campaign for Human Rights in Iran said the Tehran prosecutor's office has failed to provide any accountability to the families.
"These prisoners have committed no crimes and are in prison solely because for their opinions and beliefs. Iran should release them immediately," Ghaemi said.
Amnesty International estimates that more than 100 political prisons are being held in abusive conditions in Iranian jails after the government cracked down on protests of Mahmoud Ahmadinejad's re-election.
Meanwhile, the Baha'i International Community said this week that the imprisonment of seven Baha'i leaders-- detained at Evin prison since May 2008 -- has been extended by at least two months.
Their trial ended on June 14 but no verdict has been rendered yet.
"These innocent Baha'is have now been held for more than two years under a series of successive orders for their 'temporary' detention, which by law must not exceed two months," Baha'i community spokeswoman Diane Ala'i said in a news release.
"There is no legal basis whatsoever to refuse the request that the defendants be released on bail," she said.
Iranian authorities have detained more than 45 Baha'is in recent months, and as many as 60 Baha'is are imprisoned in Iran on the basis of their religion beliefs, the U.S. State Department has said. Iranians have also recently detained more than a dozen Christians, according to the State Department.
The Baha'i faith originated in 19th century Persia, but the constitution of today's Islamic republic does not recognize it as a religion and considers the followers as apostates.
The Iranian government denies persecuting Baha'is, who number 300,000 and form Iran's largest non-Muslim religious minority. But the Baha'is say believers in Iran are victims of systematic discrimination and targets of violence.
CNN's Moni Basu contributed to this report.