A Greek journalist covering Iran's disputed presidential election for the Washington Times has been arrested on charges of illegal activities, a friend told Reuters on Tuesday.

Iran's presidential election, in which hardline Mahmoud Ahmadinejad was adjudged the winner over his moderate rival, Mirhossein Mousavi, has led to the broadest internal unrest since the 1979 Islamic revolution.

A suicide bomber blew himself up at the mausoleum of the father of Iran's revolution, Ayatollah Ruhollah Khomeini, state media said Saturday, in an attack coinciding with more unrest over a disputed presidential vote.

Iran's Supreme Leader Ayatollah Ali Khamenei on Friday demanded an end to street protests that have shaken the country since the disputed presidential election a week ago and said any bloodshed would be their leaders' fault.

Tens of thousands of Mirhossein Mousavi's backers, wearing black and carrying candles, rallied in Tehran on Thursday to mourn those killed in mass protests against an election the defeated candidate says was rigged.

Leaders from around the world expressed concern over the situation in Iran, given new reports of government-inspired violence against election protesters and alleged voter fraud.

Tens of thousands of supporters of Iran's defeated presidential candidate Mirhossein Mousavi gathered in downtown Tehran on Monday, defying an Interior Ministry ban.

A few days ago Tehran's most famous boulevard was alive with joy and celebration as supporters of moderate presidential candidate Mirhossein Mousavi vented their desire for social and political change in Iran.

State media declared President Mahmoud Ahmadinejad the winner of Iran's election on Friday, but challenger Mirhossein Mousavi alleged irregularities and claimed victory for himself.

Opposition challenger Mirhossein Mousavi claimed victory on Friday against hardline President Mahmoud Ahmadinejad in Iran's presidential election on Friday.

Iranians streamed to polling stations on Friday in a hotly contested election and allies of hardline President Mahmoud Ahmadinejad and his main moderate challenger issued rival victory claims.

The leading moderate candidate in Iran's presidential election said some of his representatives had been denied access to polling stations on Friday to monitor the vote, the ILNA news agency reported.

If Iranian voters deny President Mahmoud Ahmadinejad re-election on Friday, it may be more a verdict on his economic performance than on his fierce rhetoric against the United States and Israel, his defense of Iran's nuclear policy or his persistent questioning of the Holocaust.

A moderate challenger to hardline President Mahmoud Ahmadinejad condemned the authorities on Monday for blocking access to the Facebook social networking site ahead of the June 12 presidential election.

A Yemeni court sentenced an Islamist to death and handed down jail sentences against two others on Monday after convicting them of seeking to work for Israeli intelligence services.