Europe on Monday stepped up pressure on Iran to end its bloody crackdown on street protests, feeling less constrained to speak out than US President Barack Obama who has made engagement with the Islamic Republic a keystone of his foreign policy. But like Obama, European leaders are wary of crossing a line that could only make matters worse for the dissenters in Teheran and could undermine efforts to contain Iranian nuclear ambitions. In a coordinated action, European countries summoned Iranian diplomats to their foreign ministries to deliver stern warnings against continuing the violence meted out to demonstrators who allege that the outcome of Iran's presidential election was rigged. The Czech Republic, which holds the rotating presidency of the 27-nation European Union, told Iran's ambassador in Prague it rejected Teheran's claims of interference in Iran's internal affairs. But it said the EU had the right to question "whether the objective criteria of a transparent and democratic electoral process have been upheld in any country." The Czech Foreign Ministry also expressed "revulsion at the documented police violence against peaceful protesters," and asked all EU countries to pass on the same message through diplomatic channels. But there has been no talk of diplomatic sanctions or curtailing business ties, which could rebound against Europe at a time when Iran is increasingly being seen as an essential partner in dealing with regional issues from Afghanistan and Iraq to the Arab-Israeli conflict. The European assertiveness also is a response to public pressure at home, where Iranian expatriates and their supporters have demonstrated in the thousands in capitals around Europe. At the same time, they need to avoid any perception of fomenting riots inside Iran and prompting Iran to take even tougher measures. The United States has little leverage with Teheran. Formal relations were broken after the Islamic revolution in 1979, and the US has imposed trade sanctions on all but humanitarian goods and basic foodstuffs. The Europeans, who have extensive trade ties with Iran, are the lead negotiators in trying to rein in Iran's nuclear program to prevent it from producing weapons, and are reluctant to use their economic leverage over the election protests. German Chancellor Angela Merkel has called on Iran to recount the votes of the disputed re-election of President Mahmoud Ahmadinejad, but stopped short of alleging electoral fraud. She also urged Iran to stop using force against demonstrators, free detained opposition members and allow free media reporting. On Monday, her spokesman Ulrich Wilhelm rejected Teheran's charges of European meddling in Iran's domestic affairs. "We have instead demanded that international laws be upheld," he told reporters in Berlin. In Paris, French President Nicolas Sarkozy has been outspoken in his criticism of the Iran's response to the demonstrations, but said doors must remain open to continue talks on Iran's nuclear program. The European Union's foreign policy chief, Javier Solana, criticized Iran's expulsion of a British reporter and the prevention of coverage of the protests by foreign media. Such tough talk has allowed Europe to take the heat for the US, which would otherwise be an easy target for the Iranian regime. The Obama administration has refrained from commenting on Iran since Saturday, when the president challenged Iran's government to halt a "violent and unjust" crackdown on dissenters. Republican members of Congress criticized his response as timid and questioned why he was allowing the Europeans to take the lead. "The last thing that I want to do is to have the United States be a foil for those forces inside Iran who would love nothing better than to make this an argument about the United States," Obama said in an interview being broadcast Monday. "We shouldn't be playing into that." That suits the Iranian leadership, which also doesn't want a fight with the American president, says Clara O'Donnell, a research fellow at the European Institute for Policy Reform in London. Iran's wrath has been particularly fierce against Britain, she said. At Friday prayers, Iran's supreme leader Ayatollah Ali Khamenei accused Western countries of blatant interference, singling out Britain as "the most evil among them." "It's interesting that the UK is being targeted, not the US," said O'Donnell. "The Iranian regime doesn't want to close off that avenue completely, and it's easier to portray the UK as the problem because at the end of the day they know the real country they need to deal with is the US." On Monday, Britain became the first country to order the evacuation of families of diplomatic staff in Teheran, saying they were unable to lead normal lives in the strife-filled city. A Foreign Office statement in London said staff were not being withdrawn, and it was not advising other British citizens to leave. The Europeans need to collaborate on their response, and the Iranian issue will be up for discussion in several multilateral meetings. Greek Foreign Minister Dora Bakoyannis, whose country currently heads the Organization for Security and Cooperation in Europe, said the developments in Iran were sure to be come up at an OSCE meeting this weekend on Corfu. Iran's first direct confrontation with Europe could come at a foreign minister's meeting this week in Italy of the Group of Eight industrialized countries and several other nations, to which Teheran is invited. But in a sign of testiness with Iran, Italy said Monday it will consider its G8 invitation rejected if Iran does not reply by the end of the day. Italy has instructed its embassy in Iran to provide humanitarian aid to protesters wounded during the clashes, pending an EU-wide proposal to coordinate assistance, said Foreign Ministry spokesman Maurizio Massari. So far the Italian Embassy has received no such requests for assistance, he said. Mousavi said that the people were entitled to protest fraud and lies, in a statement released on Sunday on the Web site of his newspaper Kalameh, quoted in AFP. "I, as one of the mourners (of the Saturday killings), invite my dear people to self-restraint. The nation belongs to you," the presidential candidate said in the statement. Meanwhile, the grisly murder of a 16-year-old protester named Neda at a demonstration in Teheran on Saturday has become the symbol of the protests The murder was captured by at least two different cameras and posted on the popular video-sharing Web site, YouTube. The longer video, which is 40 seconds in length, has been seen by over 60,000 viewers since it was posted Saturday. The video clip shows Neda falling to the ground after being shot in the chest by a single bullet. As the girl lies on the pavement staring blankly up, blood starts to seep out of her nose, and mouth. Three men bend over Neda attempting to save her life while in the background, bystanders can be heard screaming out in anguish. The video ends with her face covered in blood.