The other bombing killed six people and wounded 20 more in the town of Sinjar, 390km northwest of Baghdad, which is home to Yazidis, members of a pre-Islamic Kurdish sect.

At least 21 people were killed in two suicide attacks in Sinjar earlier this month, part of a wave of violence that has hit ethnically and religiously mixed northern Ninawa province.

In depth

  Obituary: Abdul Aziz al-Hakim
  Video: Rift appears among Iraq Shia

A surge in violence in the past two months has raised doubts about the durability of security gains, including lorry bombings that killed almost 100 people at government ministries on August 19.

There also has been a series of attacks in areas of northern Iraq where tension is high between majority Arabs, ethnic Kurds and other minorities.

Much of the violence has taken place in Ninawa.

Saturday's attacks came as thousands mourned the death of Iraq's most powerful Shia leader, following behind Abdul-Aziz al-Hakim's casket as it began the final leg of a two-day funeral procession to the southern holy city of Najaf from nearby Karbala.

Al-Hakim, who died on Wednesday of lung cancer in Tehran, was a power broker who help pave the path for the re-emergence of Iraq's Sha political majority after decades of oppression under Saddam Hussein's Sunni-dominated government.

He worked with Americans following the 2003 US-led invasion even while maintaining his ties to Iran, where he lived in exile for 20 years.

Al-Hakim was scheduled to be buried in Najaf later on Saturday.