A car bomb exploded outside a Shiite mosque packed with worshippers celebrating a major Muslim holiday Friday, and a suicide driver blew up an ambulance at the wedding of a Shiite couple south of the capital. At least 21 people died and dozens were wounded — including the bride and groom.

The attacks came a day after Iraq's most feared terror leader, Abu Musab al-Zarqawi (search), denounced Shiites in a recording that appeared aimed at sowing division ahead of the Jan. 30 elections. Shiites, long the oppressed majority in Iraq, are expected to take power in the balloting, which Sunni Muslim (search) extremists have vowed to disrupt.

Also Friday, a U.S. soldier died in an operation north of Baghdad, and an Italian soldier was killed by a burst of gunfire while patrolling in a helicopter near the southern city of Nasiriyah. Insurgents attacked several designated polling places outside Baghdad.

The car bombing at the al-Taf mosque in Baghdad occurred just as worshippers were leaving services marking one of Islam's most important holidays, Eid al-Adha, or Feast of Sacrifice. It was the second car bombing at a Shiite mosque in Baghdad this week.

An official at Yarmouk Hospital said 14 people died and 40 were wounded in the blast, which set several cars on fire and scattered debris across the street. Dozens of weeping men and women frantically searched the hospital for missing loved ones.

One distraught man sat beside the body of his 14-year-old son, covered with a sheet, and cried, "I had breakfast with him this morning. I told him, 'Let's go to your grandfather,' but he insisted on going for prayers first."

A woman dressed in a black cloak fainted as she identified her son's body in the hospital morgue.

Later in the day, a suicide driver rammed an ambulance into a crowd of Shiites celebrating a wedding near Youssifiyah, a village 12 miles south of the capital. Seven people were killed and 16 wounded.

Salah al-Ameri, the groom's cousin, said the suicide attacker stormed a garden where the wedding was taking place and detonated the vehicle. The bride and groom were hurt, he said.

The Buamer tribe has had tense relations with Sunni clans in the area, and several of their members have been killed or kidnapped by Sunni insurgents.

Differences between Shiites and Sunnis over the upcoming elections have widened the gap between the two religious communities, raising fears of even more turmoil in a nation racked by insurgency.

Shiites had no public response to Friday's bombings. Their leadership has said after previous attacks that they would not be provoked into retaliating.

Iraqi Shiites strongly support the elections, believing they will propel them to a position of influence equal to their standing as the country's majority group. They make up an estimated 60 percent of the Iraq's 26 million people.

Militants among the Sunni Arab minority have vowed to disrupt the vote, the first in Iraq since Saddam Hussein was ousted in April 2003. Some Sunni clerics and politicians have called for a boycott.

During Friday prayers at Baghdad's Umm al-Quraa mosque, a prominent Sunni cleric repeated his call for delaying the elections until the country is more secure and the 170,000 American and other foreign soldiers have left.

"How does the government call for holding elections at a time when it cannot protect places of worship in the country?" Sheikh Mahmoud al-Sumaidei asked. "It is important to have a country free from occupation forces before holding elections. Then the elections will become an Iraqi demand rather than a foreign demand and at that point we can choose our leaders."

U.S. and Iraqi officials fear a wave of violence in the run-up to the election and have announced sweeping security measures to protect voters, including closing the nation's borders and restricting traffic. American troops have stepped up security operations, arresting hundreds of people in recent weeks.

In other developments Friday:

_ U.S. troops killed three insurgents who attacked a police vehicle near the northern city of Mosul, an American military spokesman said.

_ A dozen gunmen stormed a police station in the Euphrates Valley town of Hit and blew it up, police said. No one was hurt in the attack, but the militants reportedly made off with weapons and other gear.

_ Insurgents attacked four schools in northern Iraq that will be used as polling stations, wounding two people. Three of the schools were hit by rockets and mortars, and police said they dismantled a bomb planted at the fourth.