A suicide bomber tried to kill the leader of Iraq's most powerful Shi'ite political group Monday while the main Sunni party withdrew from the country's January 30th election.

Abdul Aziz al-Hakim, whose United Iraqi Alliance is expected to dominate the vote, survived the Baghdad attack. But at least 13 people were killed. 

Earlier in the day, the Sunni Iraqi Islamic Party pulled out of the vote because of concerns over violence.  The party says more time is needed to ensure that all Shi'ites and Sunnis participate in the election.

In other election news, a new audiotape purportedly from Osama bin Laden calls for Iraqis to boycott the vote, saying those who take part will be infidels. 

The speaker also endorses Abu Musab al-Zarqawi as his deputy in Iraq.  The tape has not been authenticated.  

Some information for this report provided by AFP, Reuters.