The morning bombing in the town of Khalis in restive Diyala province also wounded 15 people, 10 of them soldiers, a security official said.

Diyala has emerged as one of the fiercest battlegrounds in Iraq, the new focus of Sunni al-Qaeda fighters who have been pushed out of western Iraq and Baghdad by a more than two-month-old US and Iraqi security operation.

In Saddam's hometown of Tikrit, gunmen shot dead the wife and daughter of Hashim Hassan al-Majid, brother of Ali Hassan al-Majid, better known as Chemical Ali, police said.

Ali, a cousin of the executed former president who served as his defence minister, is currently facing charges of genocide for killing tens of thousands of Kurds during the 1988 military campaign in northern Kurdistan.

But despite the crackdown in the capital, a string of attacks were reported Thursday.

A car bomb in the southern Jadiriyah district killed six people and wounded 18, a defence ministry official said.

Two apparently coordinated car bombs also went off in the southern district of Al-Bayaa, killing one person and wounding three.

And in Abu Chir district, also in south Baghdad, a series of mortar rounds slammed into a residential area, killing two people and wounding 11.

In the city centre, a roadside bomb killed two people and wounded five.

In northern Iraq, three Kurdish militiamen were killed and 13 wounded in a coordinated car bomb and suicide attack in the town of Zammar, northwest of the main city of Mosul.

The early morning assault targeted the offices of the Kurdistan Democratic Party of regional president Massud Barzani, a party spokesman told AFP.

On Monday, 10 people were killed and 20 wounded in a similar attack on the party's offices in the town of Tal Isquf.

The US military, meanwhile, reported that two women and two children were "unfortunately killed" in an air strike near Taji, north of Baghdad, during an operation against a suspected al-Qaeda hideout.

Four militants were also killed in the raid.

Meanwhile, the US military charged a top commander on Thursday with aiding the enemy and fraternizing with the daughter of an inmate in a US-run prison he headed in the latest scandal to hit the military in Iraq.

The US military accused Lieutenant Colonel William Steele, who before his arrest was in charge of Camp Cropper, a detention centre on the outskirts of Baghdad, of aiding the "enemy by providing an unmonitored cellular phone to detainees", the military said.

He is also accused of having unauthorised possession of classified information, maintaining an improper relationship with an Iraqi interpreter, failing to obey an order and possessing pornographic videos.

The charge sheet also accuses him of "wilfully failing to fulfil obligations as an approving authority" in the expenditure of funds.

The charges against Steele cover a period of almost 17 months between October 1, 2005 and February 22, 2007.

He has been detained in Kuwait and will face a hearing before a panel of officers to decide whether he should face charges, military spokeswoman Lieutenant Colonel Josslyn Aberle told AFP in Baghdad.

"He has been detained and is now in Kuwait. His current status is that he is in confinement and waiting for his Article 32 hearing," she said.

The military statement stressed the "charges are merely an accusation of wrongdoing. Lt. Col. Steele is presumed innocent unless and until he is proved guilty beyond a reasonable doubt of any alleged offence."

Camp Cropper has some "high-value" detainees and, before his execution for crimes against humanity on December 30, ousted dictator Saddam Hussein received medical treatment there.

Steele's arrest is the latest in a string of scandals to hit the military since the 2003 invasion.

In 2004, pictures of the abuse of detainees by low-ranking soldiers at the notorious Abu Ghraib prison west of the capital shocked the world.

The images, which included photographs of bloodied and naked prisoners smeared with excrement or being forced to perform sexual acts, stoked anti-American sentiment.

The confessionally divided province of Diyala, northeast of Baghdad, was again battered when a suicide bomber blew up a vehicle against a joint Iraqi army and police checkpoint, killing nine soldiers.

Another 15 people were wounded in the bombing in the town of Khalis, 10 of them soldiers, a security official said.

(AFP, AP)