Security officials in Iraq say a suicide bomber has killed 20 people and wounded at least 35 others when he detonated his explosives at a funeral vigil outside the capital, Baghdad.

Officials say the attack came late Wednesday just west of Baghdad.

Iraqi soldiers in Mosul, 12 May 2008

The attack comes as Iraqi Prime Minister Nouri al-Maliki flew to the northern city of Mosul to oversee the launch of an new offensive against insurgents in what is considered to be al-Qaida's last major urban stronghold in Iraq.

In a statement today, the Iraqi government says the operation is designed to purge Mosul and surrounding Nineveh province of criminals and terrorist gangs.

Officials say al-Qaida in Iraq has regrouped in the Mosul region after being forced out of Baghdad and other areas last year by U.S. and Iraqi forces.

The Iraqi military says so far, it has captured about 500 suspected insurgents in Mosul and the surrounding area.

The U.S. military says this new campaign is an Iraqi operation, but the U.S. is providing close support.

Earlier today, Iraqi medical officials said five people were killed and 22 wounded in overnight fighting involving security forces and Shi'ite militias in Baghdad's Sadr City.

The violence came days after a cease-fire accord between fighters loyal to radical Shi'ite cleric Moqtada al-Sadr and U.S.-backed soldiers.

Some information for this report was provided by AFP, and Reuters.