Thousands poured into the streets of the Iraqi capital Friday amid tight security to pay their respects to a revered Shiite leader whose death the Iraqi prime minister said left a void in the country during a "delicate and sensitive period."

The funeral service Friday at a Baghdad mosque came on the second day of a two-day funeral procession for Abdul-Aziz al-Hakim, a powerbroker whose death has a left a hole in Shiite politics in Iraq ahead of national elections in January.

"We have lost you while we are undergoing a delicate and sensitive period, and in a time when we are in need of strong men with experience and who have made great sacrifices," al-Maliki said, speaking at the airport directly to al-Hakim's casket shortly after it arrived in Baghdad.

Al-Hakim, who died Wednesday of lung cancer in Tehran, was a symbol for many of the re-emergence of Iraq's Shiite political majority after decades of oppression under Saddam Hussein's Sunni-led regime. He worked with Americans following the 2003 U.S.-led invasion even while maintaining his ties to Iran where he lived in exile for 20 years.

His death comes as insurgents have stepped up attacks, including coordinated bombings last week against government ministries in Baghdad that claimed about 100 lives. Security was tight in the city, reflecting fears that his funeral procession could become a prime target for insurgents hoping to stoke sectarian tensions.

Iraqi security forces sealed off portions of Baghdad, closing major roads linking government ministries in the Green Zone to the airport where al-Maliki and hundreds of political and religious officials gathered to meet al-Hakim's body early Friday morning.

Security forces also closed roads around the Buratha mosque in northern Baghdad.

Outside the mosque, mourners wailed and beat their chests, part of a mourning ritual, as al-Hakim's casket was brought into the building.

Iraqi state television broadcast the service, which also was carried live on a number of other Arabic stations.

Many Sunnis and some Shiites distrusted al-Hakim, seeing him as a tool of Iran in his calls for self-rule in the Shiite heartland that is also home to most of Iraq's oil.

Al-Hakim's death, however, has seen an outpouring of condolences from Iraq's biggest Sunni political party, Sunni Iraqi Islamic Party. Tariq al-Hashemi, Iraq's Sunni vice president, was among hundreds on hand for the arrival of al-Hakim's casket.

His death has left a hole in Iraq's largest Shiite political party, the Supreme Iraqi Islamic Council just five months before crucial parliamentary elections.

Al-Hakim had been grooming his son, Ammar, to take over his party. But it was unclear whether Ammar al-Hakim could hold the party together.

Al-Maliki, head of the Shiite Dawa party, had been al-Hakim's ally in a Shiite coalition that has dominated Iraq's government since 2005. But the coalition split shortly before al-Hakim's death, with al-Maliki's Dawa on one side and a smaller grouping of Shiite parties led by al-Hakim's SIIC on the other.

While eulogizing his father, Ammar al-Hakim made a thinly veiled call to al-Maliki's party to join the new coalition.

"I call upon those who have not decided to join ... to reconsider their stance in order to unite all national parties under one group that will work to defend the rights of this nation," he said.

The procession was expected to end with al-Hakim's burial in the southern holy city of Najaf.

Also on Friday, two American soldiers died of wounds sustained during a roadside bomb attack on a patrol in eastern Baghdad, the U.S. military said in a statement.

The identities of the Multi-National Corps Iraq soldiers were being withheld pending notification of next of kin, and the incident was under investigation, the statement said.

The deaths raise to at least 4,337 members of the U.S. military who have died in the Iraq war since it began in March 2003, according to an Associated Press count.