Protests are taking place in Iran following the arrest of opposition leaders. Chants of “death to the dictator” can be heard and clashes have been reported in Tehran.
Iran security forces fired teargas and clashed with opposition supporters in Tehran according to the opposition website Kaleme.
“Security forces and people in civilian clothes clashed with demonstrators in Tehran to disperse them,” the website reported.
The protests follow the detention of opposition politicians Mir Hossein Mousavi and Mehdi Karroubi on Monday.
Saeed Valadbaygi, a journalist who fled Iran in 2009, told Channel 4 News the arrests showed the Government’s weakness: “The important issue is that they have a great fear and this fear prevents them from confirming and taking responsibility for these arrests.
“Even though these two people and their wives were already under house arrest, and recent reports claim their transfer to Heshmatiyeh prison, government officials still ignore the issue.”
Iran’s authorities have declined to confirm the whereabouts of two opposition leaders, whose supporters say were arrested amid efforts to rekindle street protests that were crushed more than a year ago.
In Washington, White House spokesman Jay Carney called Iran’s reported detention of opposition leaders “unacceptable” and urged that they be released.
Human rights groups in the UK told Channel 4 News the authorities must reveal the men’s location.
Amnesty International UK Director Kate Allen said: “Mir Hossein Mousavi and Mehdi Karroubi, and their wives, appear to have been subjected to enforced disappearance.
“This is against international and Iranian law. The Iranian authorities should immediately make clear their whereabouts.
“If they are being detained arbitrarily, they should be released. Iran must stop this ceaseless intimidation and harassment of political opponents, peaceful protesters and advocates of human rights.”
Read more: Iran - inside the Islamic state
Mir Hossein Mousavi and Mehdi Karoubi had been living under virtual house arrest since they called a rally for 14 February to support uprisings across the Middle East
They were arrested along with their wives last Thursday, say their supporters, who plan an unauthorised demonstration in Tehran to demand their release.
At his weekly news conference, Foreign Ministry spokesman Ramin Mehmanparast declined to confirm or deny the arrests, calling the situation a “domestic issue” which was being exploited by foreign governments to show Iran in a bad light.
“The news related to some people (Karroubi and Mousavi) will be looked into by judiciary officials and within the legal frameworks,” Mehmanparast said.
“This issue cannot be used as a pretext by America and some other western countries…to try to divert everyone’s attention to unreal issues.”
We will only be in a position to deny the arrest and incarceration of our parents if we are able to have an immediate visit with them. Mousavi’s daughters
Both men, who spearheaded protests against President Mahmoud Ahmadinejad’s re-election in June 2009, face calls from parliament to be tried and hanged for what government supporters say is their role in stirring “sedition”.
The authorities’ reluctance to confirm their whereabouts shows Iran’s sensitivity to taking aggressive action against the men who called huge crowds onto the streets in 2009 and remain rallying points for opposition to Ahmadinejad’s government.
Mousavi’s daughters issued a statement on opposition website Kaleme, rejecting a report on a semi-official state news agency that denied the arrests.
“We will only be in a position to deny the arrest and incarceration of our parents if we are able to have an immediate visit with them without threats and without the presence of security forces,” they said.
Read more: Arab revolt - the Middle East uprisings
Opposition supporters were due to meet on Tuesday afternoon for a march in central Tehran, a possible flashpoint as the authorities have warned against holding any further “illegal” gatherings.
Two people were shot dead at the 14 February rally – deaths each side has blamed on the other.
Large numbers of security forces were deployed on previous protest days.
Opposition website Iran Green Voice said several coffee shops near the site of the march were closed down and sealed by police on Monday as they were suspected of being meeting places for government opponents.