Sunni Arab clerics in Iraq have issued a religious edict or fatwa urging Iraqis to vote in Thursday's crucial parliamentary election.

The edict Tuesday has the support of hundreds of Sunni clerics. It raises hope that Sunni Arabs will vote in much higher numbers than in January's election for an interim assembly, which they mostly boycotted.

Some insurgent groups have called on their loyalists not to attack polling stations. But despite the call, tough security measures will be in place.

Outside Iraq, expatriates began casting their ballots Tuesday in 15 countries.

In other political developments, Iraq's president, Jalal Talabani, says he will not seek a second term as president, because the office is largely ceremonial and lacks real powers.

Meanwhile, gunmen assassinated a prominent Sunni Arab politician, Mizhar al-Dulaimi of the Free Progressive Iraqi Party, in the western city of Ramadi. Also today, four American soldiers were killed in a bomb blast northwest of Baghdad.

Some information for this report provided by AP, Reuters.