A car stopped at a checkpoint before detonating, killing the driver, reported Iraqi police officer Muhanad Mahmud and US occupation authorities on Tuesday.
Military officials said the driver was killed. Two security guards were among those wounded.
Last week Ankara's parliament approved a move to deploy Turkish troops to its occupied neighbour, sparking outcries from Iraqis.
In Ankara, a Turkish Foreign Ministry spokesman strongly condemned the attack and said the incident showed "how grave the security situation in Iraq is" and "how strong the need is for everyone to immediately contribute to ensure security and stability in the country."
Iraq appears to be heading for the nightmare scenario of disintegration that many predicted before the US-led invasion last March.
Forces loyal to popular Shia cleric Muqtada al-Sadr clashed overnight with another Shia group, resulting in one person being killed.
Twenty-four other people were wounded when al-Sadr’s supporters tried to seize control of the holy sites in the southern city of Karbala.
Medics at the city’s main hospital said one person was in serious condition.
The incident occurred when about 100 members of al-Sadr’s army tried to capture control of the mausoleums of two venerated figures in Shia Islam, the seventh century Imam Husayn, and his brother Abbas.
The militiamen, known as the Mahdi Army, were pushed back to a nearby mosque by supporters of Shaikh Ali al-Sistani, a leading member of the Hawza, the centre of Iraq’s Shia education and religious authority.
Al-Sistani followers, backed by Iraqi police, dislodged the Mahdi Army members, who then headed to a nearby field.
US-led occupation forces did not intervene.
Foreign forces out
Al-Sadr also reiterated calls for a future Iraqi government to be chosen by Iraqis and a schedule for an occupation pullout.
Muqtada Al-Sadr's Mahdi Army
refuses to give up its weapons
Al-Sadr, who announced a "parallel" government in a Friday sermon last week, said the people of Iraq would choose their own leadership.
In a press conference on Tuesday, the anti-occupation cleric urged peaceful demonstrations to be held against the current US-appointed Iraqi Governing Council.
Al-Sadr said there was no cooperation between his forces and occupation troops.
"I advise these occupation forces to schedule a prompt exit from Iraq," al-Sadr told a press conference in the Shia holy city Najaf, 180 km south of Baghdad.
Al-Sadr urged Iraqis to cooperate and avoid inter-communal fighting.
In related news, Iraq's oil minister, Ibrahim Bahr al-Ulum, and a senior aide have survived an assassination attempt, said an Iraqi oil official on Tuesday.
The attack took place in the capital on Sunday, said the official. Members of Iraq’s US-appointed Governing Council have increasingly come under attack.
Akila al-Hashami, a member of the Governing Council, died from wounds sustained after she was shot last month.
Six months after US and British forces ousted former Iraqi President Saddam Hussein, Washington is still struggling to maintain law and order and restore basic services in Iraq.
Meanwhile, two US soldiers died in a military vehicle accident in Baghdad on Monday and another was found dead, floating in the Euphrates river in the northwestern Iraqi town of Haditha, occupation authorities announced on Tuesday.