The Islamic State of Iraq and the Levant (ISIL) has released about 200 mostly elderly members of northern Iraq's Yazidi minority who had been held for months.

The Yazidis were freed on the frontline southwest of the city of Kirkuk on Saturday and met by Kurdish Peshmerga forces who brought them to a health centre in Altun Kopri, on the road to the Kurdish regional capital of Erbil.

Yazidis follow a religion that predates Islam and Christianity and originated in Mesopotamia, which encompassed modern-day Iraq and parts of neighbouring states. 

In a statement after the release of the Yazidis, Peshmerga member Sihamee Omar told Al Jazeera that the Yazidis, most of them above 50 years of age, had been held for almost five months.

They were transferred in a convoy on Sunday to a camp in Dohuk, where they were to be reunited with their relatives.

"These men and women had been held in Mosul," Khodr Domli, a leading Yazidi rights activist, told the AFP news agency at the health centre.

"Some are wounded, some have disabilities and many are suffering from mental and psychological problems," he said.

According to officials from Kirkuk and Erbil, the group was moved from Mosul via Hawija and freed at the Maktab Khaled entrance to Kirkuk.

Thousands still missing

Al Jazeera's Jane Arraf, reporting from Baghdad, said that Kurdish activists were not sure why elderly Yazidis were released.

"They believe ISIL has let them go, because the group could not take care of these elderly people anymore," she said.

"ISIL claims that it is a state, which brings the responsibility for them to take care of people."

Al Jazeera's Mohammed Adow, reporting from Erbil, said the conditions for the release were unclear.

ISIL attacked Yazidi villages in August [Sherien Emam/Al Jazeera]

"What we know is that thousands of Yazidis, mainly girls, remain at the hands of ISIL fighters," he said.

Nasou Afdel, whose father was released, told Al Jazeera that his mother and two sisters were still missing.

"We ask the Kurdish Regional Government and the Baghdad government to reach out to us and help us and help all Yazidis because they are left with noting right now," he said..

Several infants with serious illnesses were among the released, according to a Reuters reporter.

Dozens of Kurdish doctors and nurses provided emergency care at the Altun Kopri health centre, where Yazidis who had heard the news started to mass at the gates, hoping to be reunited with missing relatives.

"We have dispatched laboratory teams to check their blood, to control for things such as polio and possible contagious diseases," said Saman Barzanji, director general of the Erbil health department.

"Another team is here to handle the people's immediate health needs. We have also deployed ambulance teams to dispatch emergency cases to hospital," he said.

An elderly man speaking to reporters said he had been living in constant fear for his life in captivity.

Another man recalled how they had been moved from one place to another in northern Iraq since being captured in early August.

"It was so hard, not only because of the lack of food but also because I spent so much time worrying," he told AFP.

Several children were among those released [Sherien Emam/Al Jazeera]

ISIL carried out a June offensive that began in Mosul and overran much of Iraq's Sunni Arab heartland north and west of Baghdad, sweeping security forces aside.

Thousands of Yazidis were among those killed or captured.

Those who could flee escaped to the autonomous Kurdistan region, where many are living in camps along with other religious and ethnic minorities, as well as Sunni Muslims displaced by ISIL.

Concern for the Yazidis was cited by the US as a reason for its decision to launch air strikes against ISIL [Sherien Emam/Al Jazeera]

Source: Al Jazeera and agencies