The UK has demanded the immediate release of Iranian staff at its Tehran embassy who were arrested on Saturday. Iranian media earlier reported that eight local staff at the mission had been detained for their "considerable role" in post-election riots. UK Foreign Secretary David Miliband called the arrests "harassment" and dismissed the allegations as baseless. Relations between the countries are strained after Tehran accused the UK of stoking unrest, which London denies. Iran has repeatedly accused foreign powers - especially Britain and the US - of stoking the unrest that swept the country after the 12 June election, which handed President Mahmoud Ahmadinejad a decisive victory. In the fallout of the crisis, Tehran expelled two British diplomats in the past week, and the UK has responded with a similar measure. Strained relations Mr Miliband said about nine employees had been detained in total, but some had been released. "We are still concerned about a number of them who to our knowledge have not been released... The numbers are changing hour by hour," he said on the sidelines of a European security meeting on the Greek island of Corfu. "The idea that the British Embassy is somehow behind the demonstrations and protests that have been taking place in Tehran in recent weeks is wholly without foundation," he added. A strong protest had been made directly to the Iranian authorities, but there had been no response. Mr Miliband said he would discuss the arrests with his European Union colleagues. "All European countries have made clear that they want to stand together in standing up for the diplomatic principles that are important for our diplomatic activity all over the world," he said. The arrests were first reported by Iran's semi-official Fars news agency. "Eight local employees at the British embassy who had a considerable role in recent unrest were taken into custody," Fars said, without giving a source. Some 17 people are thought to have died in street protests after the disputed presidential poll, which the opposition complains was rigged. Poll verdict Meanwhile, Iran's powerful Guardian Council was due to give its verdict on the result of the disputed presidential election. But the BBC's Jeremy Bowen in Tehran says there is much politicking taking place behind the scenes, and that the five-day deadline for the Guardian Council to return its verdict may be extended. Our correspondent says there is an attempt to form a committee - including the disappointed presidential candidates - to oversee the recount of 10% of the votes, a move which they are resisting. Another parliamentary committee is holding discussions with the grand ayatollahs in an attempt from pro-Ahmadinejad forces to put on a show of unity, he adds. But opposition leader Mir Hossein Mousavi has not backed away from his claim that the election result was fraudulent, and has refused to support the Guardian Council's plan for a partial recount. Mr Mousavi has been calling for a full re-run of the vote, but said on Saturday that he would accept a review by an independent body. However the Guardian Council has already defended President Ahmadinejad's re-election, saying on Friday that the presidential poll was the "healthiest" since the Iranian revolution in 1979. Source:BBC