Iranian authorities have released the children of two prominent opposition figures, Mir Hossein Musavi and Mehdi Karrubi, after briefly detaining them for questioning.
The authorities on February 11 raided the apartment of Musavi's daughters, Narges and Zahra, and took them in for questioning.
Officials told Iranian media that the two women had been summoned "to give some explanations."
Later Karrubi's website, Sahamnews, reported that security officials raided the residence of his son, Mohammad Hossein Karrubi.
He also was freed hours after being taken in for questioning.
The three have campaigned for their parents' release from house arrest.
Former presidential contenders Musavi and Karrubi had been under house arrest since early 2011.
Musavi and fellow reformist Mehdi Karrubi were presidential candidates in June 2009 election, which gave President Mahmud Ahmadinejad a second term in office. Musavi and Karrubi claimed the election was rigged.
Meanwhile, UN experts on February 11 also called for Musavi and Karrubi's release.
A Paris-based spokesman for Musavi broke news that security forces had raided the Tehran apartment of Narges, 27, and Zahra Musavi, 37.
The spokesman, Ardashir Amir Arjmand, told RFE/RL's Radio Farda it was still unclear where the two women had been taken.
Musavi and Karrubi were recognized as leaders of Iran's Green Movement, a series of street protests in which protesters demanded Ahmadinejad's removal from office following the 2009 vote.
Both men were detained after they called on their followers to stage rallies in support of Arab uprisings in Tunisia and Egypt two years ago.
Since then, Karrubi and Musavi, along with his wife Zahra Rahnavard, have been held under house arrest.
Iranian hard-liners have urged the judiciary to execute Musavi and Karrubi.
Musavi and Rahnavard have one other daughter. The three sisters said in a statement last month that authorities had for weeks denied Musavi and Rahnavard contact with their children.
Amir Arjmand said Musavi's family members "have been under pressure by security forces for quite a long time" and have been "repeatedly threatened."
"Musavi's second daughter, Zahra Musavim, was a university professor. But she has been unlawfully banned and dismissed from the university. Musavi's third daughter, Narges, too, has been subject to pressure and harassment by security forces," Arjmand said.
Amir Arjmand, however, pointed out that that the sisters have not been planning to stage a rally or gathering to mark the second anniversary of their parent's house arrest.
Musavi, 70, served as Iran's prime minister in the 1980s. Sources close to Musavi say he was treated for a heart problem in August.
With additional reporting by Reuters, AFP, and AP