Iraqi police say the death toll from triple suicide blasts at a Shi'ite mosque in Baghdad has reached at least 79 people, with more than 160 others wounded.
Security officials say three suicide bombers dressed as women blew themselves up Friday as worshippers were leaving the Baratha mosque in northern Baghdad after Friday prayers.
Authorities urged Iraqis in the capital to donate blood for those wounded, and to avoid gathering in large crowds near mosques and markets, due to the ongoing sectarian violence.
United Nations Secretary-General Kofi Annan strongly condemned the bombing, saying it clearly demonstrates that there are forces in Iraq determined to inflame sectarian violence and exploit difficulties in forming the new government.
The U.S. ambassador to Iraq, Zalmay Khalilzad, in an interview with the BBC, urged Iraqi politicians to break the deadlock and build a national unity government. He also offered condolences to the people of Iraq, saying that terrorists who murder innocent people are the enemies of all faiths and of all humanity.
One of the main sticking points is Iraqi Prime Minister Ibrahim al-Jaafari, who is refusing to step down as the Shi'ite nominee for a second term.
Iraq's Kurdish and Sunni Arab leaders say he has not done enough to ease the sectarian violence.
Meanwhile, the U.S. military said three American soldiers have been killed in separate attacks in Iraq.
One U.S. serviceman died Friday of wounds sustained when his patrol came under small arms fire in western Baghdad. The other one was killed Thursday when his combat patrol hit a roadside bomb near Beiji north of Baghdad. Also Thursday, a Marine died during an operation in al Anbar province.