LONDON - Britain ordered the expulsion of two Iranian diplomats on Tuesday, a day after two UK diplomats were ordered to leave Iran. The Iranians ordered the expulsion of the two officials for "activities inconsistent with their diplomatic status" - diplomatic language for spying. British Ambassador Simon Lawrence Gass had pressed the Iranian authorities to give specific examples of what "activities" the diplomats had been involved in, but they declined to offer any. The Foreign Office has not issued the identities of the two expelled individuals except to say that they were diplomats and not support staff. A Foreign Office representative said it summoned Iranian Ambassador Rasoul Movahedian on Tuesday and told him two Iranian diplomats holding equivalent positions in London were being asked to leave by the end of the week. The Foreign Office representative said the action was "regrettable" but the UK had been forced to respond. Prime Minister Gordon Brown told Parliament he had no choice but to react after Teheran made allegations that were "unjustifiable" and "absolutely without foundation." Brown also said the result of the Iranian presidential elections should reflect the aspirations and choices of the people there. "The onus is on Iran to show the Iranian people that recent elections have been credible and that the repression and curtailment of democratic rights that we've seen in the last few days will cease," he said. Conservative Party leader David Cameron supported the decision to expel the Iranian diplomats. "The expulsion of diplomats by Iran is clearly not acceptable and the British government was absolutely right to respond," Cameron said. Britain has been blamed for the unrest on the streets of Teheran and other cities, with Iran singling out the UK in its condemnation of what it calls meddling by foreign powers in its affairs. On Tuesday, protesters mostly stayed off the streets of Teheran as troops patrolled the city and helicopters clattered overhead to prevent any gatherings. That day was declared an unofficial national strike by the defeated presidential candidate Mir Hossein Mousavi and his backers, an echo of tactics used in the 1979 Islamic Revolution. Sources said that in the provinces, many prominent and respected figures openly or secretly backed the call. One Teheran resident told The Jerusalem Post dissidents would stage another protest rally in a location he did not want to disclose over the phone. According to the source, the government has clamped a military crackdown on the city, with security forces stationed at every corner. "Today [Tuesday], I went to the mosque to pray for the brave people who gave their lives for our country. But the Basiji [paramilitary] forces standing by did not let me in. I looked over at one of them; the young man was no more than 14 or 15 years old. "As I tried to pass him, he held up a club in my face telling me to move along," his voice cracked as he went on. I said to him, 'You are like my child,' let me through so I can pray for young people who are not here with us today. Then he told me in a sarcastic voice that 'terrorists don't need your prays, old man...' When I got back into my car I could not stop crying." In Washington, President Barack Obama said the US and the rest of the world was "appalled and outraged" by Iran's violent efforts to crush dissent. "I have made it clear that the United States respects the sovereignty of the Islamic Republic of Iran, and is not interfering in Iran's affairs," Obama said. "But we must also bear witness to the courage and dignity of the Iranian people, and to a remarkable opening within Iranian society. And we deplore violence against innocent civilians anywhere that it takes place." Across the world, governments and diplomats were increasingly lining up on opposite sides in the Iranian showdown. In a boost for the embattled regime, Russia said it respected the declared election result. But France summoned Iran's ambassador to express concern about the "brutal repression" of protesters in Teheran. The US and many European countries have refrained from challenging the election outcome directly, but have issued increasingly stern warnings against continuing violence meted out to demonstrators. UN Secretary-General Ban Ki-moon demanded an immediate end to "arrests, threats and use of force." Iran's official news agency, IRNA, reported that the Iranian Foreign Ministry rejected Ban's remarks and accused the UN chief of meddling. State television said Supreme Leader Ali Khamenei agreed to extend a deadline by five days for submitting election complaints. But the Iranian regime still appeared determined to crush the post-election protesters, rather than compromise. In another sign of the regime's crackdown, Ebrahim Raisi, a top judicial official, confirmed Tuesday that a special court has been set up to deal with detained protesters. "Elements of riots must be dealt with to set an example. The judiciary will do that," he was quoted as saying by the state-run radio, which gave no further details. The judiciary is controlled by Iran's ruling clerics. Two prominent Iranian opposition figures took their case to Europe on Tuesday. Nobel Peace laureate Shirin Ebadi asked EU officials in Brussels not to negotiate or hold meetings with Iranian leaders until the crackdown stops. In Rome, filmmaker Mohsen Makhmalbaf held a news conference, saying he had been asked by Mousavi's aides to spread the word on what is happening in Iran. Makhmalbaf said that even if President Mahmoud Ahmadinejad manages to govern for the next four years, "he will not have one day of quietness." He said protesters would resort to general strikes and civil resistance. Iran's Press TV said Tuesday that the government had refused a permit for a protest by university students outside the British Embassy in Teheran. Opposition protests have become smaller, after a huge opposition rally a week ago, though demonstrators have been more willing to confront Iranian troops.