re-elected as president of Iran with a resounding victory, the electoral commission says. With more than 80% of results in, the commission said he won 63% support in an election marked by high turnout. Reformist Mir Hossein Mousavi also claimed victory, calling the result a "dangerous charade", as supporters vowed to appeal for a re-run. Police have sealed off Mr Mousavi's campaign HQ, preventing his supporters from holding a news conference. One opposition newspaper has been closed down and BBC websites also appear to have been blocked by the Iranian authorities. Mr Mousavi was hoping to prevent Mr Ahmadinejad winning more than 50% of the vote, in order to force a run-off election. However, the Iranian election commission said Mr Mousavi's share of the vote was around 34%. Earlier, the state news agency Irna declared Mr Ahmadinejad the "definite winner", and his campaign manager was quoted as saying "any doubts cast on this victory will be treated as a joke by the public".

Danger of 'tyranny'

Mr Mousavi issued a statement shortly after 1300 local time (0930 GMT) on Saturday, after the scale of the hardline president's victory became clear.

The former prime minister dismissed the election result as deeply flawed.

Police presence

Although there were few signs of organised dissent on the streets, police in Tehran moved to prevent protests on Saturday. There was heavy security around Mr Mousavi's campaign headquarters and reports that at least one rally for Mr Mousavi was broken up by police using truncheons against small groups of people.The AFP news agency said police dispersed opposition supporters on Saturday morning, quoting a senior police official as saying: "The time of dancing and shouting is over." One opposition supporter who gave her name as Shirin, told the BBC she still had confidence Mr Mousavi would become president.

"But he advised us, the supporters, not to do anything harsh or trying to... clash with Ahmadinejad's supporters," she said. Our correspondent says the reaction of Iran's Supreme Leader Ayatollah Ali Khamenei will be extremely important. BBC Iranian affairs analyst Sadeq Saba says the result means that hope for peaceful reform in Iran may die for a long time.

Large turnout

There had been a surge of interest in Iran's presidential election, with unprecedented live television debates between the candidates and rallies attended by thousands.

There were long queues at polling stations, with turnout said to be higher than 80%.

Four candidates contested the election, with Mohsen Razai and Mehdi Karroubi only registering a small percentage of votes.

President Ahmadinejad draws support mainly from the urban poor and rural areas, while his rivals have support among the middle classes and the educated urban population. Iran is ruled under a system known as Velayat-e Faqih, or "Rule by the Supreme Jurist", who is currently Ayatollah Ali Khamenei.

It was adopted by an overwhelming majority in 1979 following the Islamic revolution which overthrew the autocratic Western-backed Shah.

But the constitution also stipulates that the people are the source of power and the country holds phased presidential and parliamentary elections every four years.

All candidates are vetted by the powerful conservative-controlled Guardian Council, which also has the power to veto legislation it deems inconsistent with revolutionary principles.