Iranian security forces have arrested a son of opposition leader Mehdi Karoubi, his website reported today, a week after his supporters took to the streets in their first demonstrations in more than a year.
"Last night security forces entered the house of Ali Karoubi and arrested him and his wife, Nafiseh Panahi" Sahamnews website said. Ms Panahi was later released but there was no further news of her husband, it said.
Sahamnews said there were concerns for Mehdi Karoubi himself after security forces raided his house last night and confiscated documents and books.
"After last night's incident and despite many efforts there is no news of the fate of (Mehdi) Karoubi and his wife," the website said.
Mehdi Karoubi has been under virtual house arrest for more than a week after calling for supporters of his reformist Green movement to hold a rally on February 14th, the first event of its kind since December 2009. More demonstrations were held on Sunday.
Sahamnews said security forces were also seeking another of Mr Karoubi's sons, Hossein, who has been very outspoken since his father's house arrest.
Along with Mirhossein Mousavi, the 73-year-old Mr Karoubi heads the "Green" opposition movement which staged huge protests after the 2009 re-election of President Mahmoud Ahmadinejad which they said was rigged.
The government denied the charge and crushed those demonstrations, accusing the Green movement of trying to overthrow the Islamic system with the support of Iran's foreign enemies.
Two people were shot dead at the February 14th rally in Tehran, deaths that government supporters blamed on "terrorist" elements among demonstrators but which the opposition movement said were evidence of state brutality.
Government supporters have called for both opposition leaders to be tried and executed, but so far authorities have chosen to isolate rather than arrest them, possibly wary of giving them greater publicity and angering their supporters.