The gunmen, masquerading as Iraqi soldiers, broke into the southeast Baghdad home of Sheikh Fadel Sarhid Ali around 4:00 am (0100 GMT) and shot the tribal leader and his sons before escaping, said police.

These attacks were shortly followed by the assassination of a high ranking official in the ministry of industry, Radi Ismail Jawad, and the former chief of traffic police, General Mahdi Kassem -- both in Baghdad.

Leaders from all religious and political affiliations have been regularly targeted by death squads in the strife following the fall of Saddam Hussein's regime in 2003.

The latest bloodshed came as the death toll for a car bomb aimed at police forces on a busy market street the day earlier in Kirkuk rose to 22 dead, include four police, with 28 wounded.

In a recent meeting of Iraqi factions, the restoration of internal security and the buildup of the Iraqi army were given high priority -- as well as calls for a timetable for the withdrawal of foreign troops.

In televised remarks in Washington, US Secretary of State Condoleezza Rice indicated that troop reductions could be imminent.

"The president has said that as soon as Iraqi forces are ready, we want to see a reduction in our own forces, and I think those days are going to be coming fairly soon when Iraqis are going to be more and more capable of carrying out the functions to secure their own future," Rice told Fox News Channel.

About 159,000 US troops are currently deployed in Iraq ahead of the vote that is expected to produce the country's first democratically-elected permanent government since the overthrow of the Saddam Hussein dictatorship in April 2003.

Once the election is over, the number of US troops is expected to be brought back to about 138,000, which US defense officials refer to as the "baseline."

Rice insisted that for the US troop withdrawal to begin, Iraqi security forces should demonstrate their ability to "hold territory."

The remarks come amid increasing discussion over the presence of US troops in Iraq from not just the Iraqi end but from the US Congress as well.

A poll published Tuesday also showed that 63 percent of Americans were in favor of bringing troops home from Iraq in the next year. Another 61 percent doubted that democracy and stability would come to Iraq.

US authorities are eager to show that a steady transfer of responsibility to the Iraqis is ongoing, with regular announcements of successful joint military operations between US and Iraqi forces as well as the handover of bases.

"The Iraqi Army has been the main effort in many of our operations," said Colonel John L. Gronski of the US marines in Ramadi in statement Tuesday. "They continue to exhibit professionalism and resolve in securing their country."

A ceremony handing over a massive palace complex of Saddam that had housed three different US military units since the invasion to the Iraqi government was disrupted on Tuesday by an unsuccessful mortar attack.

The shell, which did not explode, briefly sent attendees running for cover, including US ambassador to Iraq Zalmay Khalilzad and US commander General George Casey.

Meanwhile in the northern city of Kirkuk, police and civilians sifting through the rubble of car bomb discovered three more bodies, raising the toll from Tuesday's attack to 22 dead.

A small explosion and shooting of a policeman in a crowded market area was used to lure police into an ambush when a car bomb rammed a patrol car arriving at the scene.

The attack took place in a largely Turkoman area in a city known for its ethnic tensions between Sunni Arabs, Kurds and Turkomans.

Iraqi government efforts to combat the insurgency has taken a new tack over the past two days with an offer by President Jalal Talabani, while in Cairo, to negotiate with insurgents.

He followed this up with a landmark visit to Iran that concluded Wednesday with assurances from the Iranians to ensure Iraq's security.

"Iran is interested in our security just as it is interested in its own security," Talabani said as he was seen off by hardline Iranian President Mahmoud Ahmadinejad. "They all said one thing to me: that there are no limits to Iran's cooperation with and support for the Iraqi people and government."

Iran has often been accused of supporting insurgent attacks against US and British forces, a charge Iran denies. (AFP, Reuters)