Muslim clerics in Iraq today used Friday prayers to preach their final instructions to their followers on how to vote during tomorrow's referendum on the draft constitution.

Amid a curfew and strict security clampdown ahead of the poll that left streets empty, Shia imams transmitted the word of the community’s most powerful cleric, Grand Ayatollah Ali al-Sistani: Go to the polls and vote "yes".

But the message among the Sunni Arab minority was more muddled, after the last minute decision by the Iraqi Islamic Party, the largest Sunni Arab political party, to change its mind and support the constitution.

Yesterday, Iraqi Islamic Party banners urging a "no" vote were taken down from where they had been hanging, near monuments such as Baghdad's Grand Imam mosque.

In response, Sunni insurgents launched a wave of bomb attacks against the homes and offices of prominent Islamic Party members.

In Tikrit, Saddam Hussein’s home town, the preacher at the main mosque denounced the Islamic Party, saying it "broke the nationalist ranks in return for nothing."

Sheik Rasheed Yousif al-Khishman told worshippers at Tikrit’s al-Raheem mosque to vote against the "infidel constitution written by foreign hands". Mosques throughout the town told people to cast "no" votes, and warned "anyone who does not go to the polls is not considered a Sunni".

But in the nearby town of Samarra, Sheik Adil Mahmoud, of the Association of Muslims Scholars, was more tempered in his sermon. "I will go to the polls and vote ’no’, but I leave the choice to you to follow your political preferences," he told worshippers. "I respect the opinion of the Iraqi Islamic party and any other party".

In Baghdad’s biggest Sunni neighborhood, Azamiyah, several hundred demonstrators marched towards the district’s biggest mosque, Abu Hanifa - a centre for the Iraqi Islamic Party - waving banners saying "No to the Constitution", and chanting slogans describing the party’s chief, Mohsen Abdul-Hamid, as a traitor.

Before dawn, someone threw a grenade at the house of the main cleric of the Abu Hanifa Mosque, Sheik Muayad al-Azami, but no one was hurt in the explosion. The night before, his son was threatened by Sunni opponents during prayers, al-Azami said.

Militants exploded a bomb outside the Islamic Party’s office in central Baghdad, then set fire to the party’s main office in Fallujah, police said. No injuries were reported.

Until now it has been rare for Sunni insurgents to attack a Sunni political party. Iraqi army Major Salman Abdul Yahid said however that the attacks were expected. "Insurgents had threatened to attack the group and its leaders to get revenge," he told The Associated Press.

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