Militants ambushed a convoy carrying Iraq's deputy interior minister Tuesday, killing a bodyguard and wounding the deputy's son and two other people, an official in the ministry said.

The government said it captured a former member of Saddam Hussein's regime who was believed to be funding the insurgency.

Outgoing interim Prime Minister Ayad Allawi (search), meanwhile, has asked U.S. Gen. George Casey to review the cases of Iraqi detainees, arguing that many are in custody even though they do not face formal charges.

Deputy Interior Minister Gen. Tariq al-Baldawi (search) escaped unhurt after gunmen in two cars opened fire on his convoy in Baghdad's western Adel neighborhood, according to a ministry official who declined to be identified for fear of reprisals.

The government said it captured Fadhil Ibrahim Mahmud al-Mashadani (search), a high-ranking member of Saddam's Baath Party (search), at a farm northeast of Baghdad. It said he worked as the former leader of the military bureau in Baghdad under Saddam.

Al-Mashadani was "among the main facilitators of many terrorist attacks in Iraq," the government said. "Mashadani is believed to be personally responsible for coordinating and funding attacks against the Iraqi people."

The Iraqi government also said it captured an insurgent who confessed to trying to cross into Syria to collect a car bomb for detonation in Iraq, and the Iraqi detainee had "links" with Syria's intelligence services.

Border guards arrested the man April 10 as he tried to cross into Syria, the Defense Ministry said.

Syria repeatedly has denied that it supports or intentionally harbors Iraqi insurgents or would-be insurgents but says it cannot completely seal its long border with Iraq.

In his letter to Casey about reviewing the cases of detainees, Allawi specifically mentioned several followers of Shiite cleric Muqtada al-Sadr (search) and a large number of Sunni imams.

"Resolving such issues will play a big role in consolidating national unity ... and in making the citizens believe in the government's good intentions to provide security and stability for all Iraqis," a statement from Allawi's office said.

Allawi proposed forming a committee made up of the ministers of interior, justice and human rights, as well as coalition representatives, to study the issue. It was unclear if he had the backing of Iraq's new leaders, who are forming a government that will take over within weeks.

The request came as Defense Secretary Donald H. Rumsfeld (search) arrived in Baghdad on Tuesday for his second visit in three months. He urged Iraq's leaders to avoid delays on either the political or security front.

"It's important that the new government be attentive to the competence of the people in the ministries and that they avoid unnecessary turbulence," Rumsfeld said.

Rumsfeld met with Interim President Jalal Talabani (search), a former Kurdish rebel leader, and Ibrahim al-Jaafari (search), the Shiite Muslim who was designated interim prime minister last week.

In Warsaw, Polish Defense Minister Jerzy Szmajdzinski (search) said the government wants its 1,700 troops to leave Iraq after the authorizing U.N. resolution expires at the end of the year. While Polish officials have indicated their force would leave after the expiration, Szmajdzinski's remarks were the most definitive about when that might happen.

However, Szmajdzinski said the mission could be extended if the Security Council votes a new mandate for next year or if the Iraqi government asked Poland to keep its troops there.

The Polish-led security force has about 4,600 troops and covers three provinces in central Iraq. Seventeen Polish soldiers have been killed in Iraq.

In other violence, gunmen in the northeastern city of Kirkuk (search) wounded two members of a police patrol late Monday, police Brig. Sarhad Qader said. On its Web site, the militant group Ansar al-Sunnah Army (search) claimed responsibility for machine-gun fire attacks on three Iraqi police cars in Kirkuk Monday evening.

Attackers also placed a bomb in the undercarriage of a doctor's car that exploded as the physician entered a store to buy bread, sparing him but wounding two nearby civilians, Qader said. It was unclear why militants, who have focused attacks on U.S. and Iraqi forces and government workers, targeted the doctor. Kirkuk is 180 miles north of Baghdad.

In the northern city of Mosul, a suicide car bomber targeting a U.S. convoy blew himself up, killing five civilians and wounding four, officials said.

The U.S. Embassy announced the kidnapping of an American citizen. The unidentified American was a contract worker abducted at about noon Monday, a spokesman said.

On Tuesday, the U.S. Embassy said it had received no claim of responsibility or demands. The American's identity, hometown and employer were not released.

Residents of a small town north of Qaim (search) — a city on the Syrian border where insurgents attacked a U.S. military base with three car bombs late Monday — reported the sounds of gunfire and heavy explosions overnight.

Hamid al-Alousi, director of Qaim hospital, said his facility received nine bodies and nearly two dozen wounded in reported violence at the village of Ish. U.S. military officials had no immediate information.

Iraqi Vice President Adel Abdul-Mahdi (search) met Tuesday with Grand Ayatollah Ali al-Sistani (search), a leading Shiite leader who called on voters to cast ballots during the country's historic Jan. 30 elections. The country's other vice president, Ghazi al-Yawer (search), a Sunni Arab, met with al-Sistani on Monday.

"As we know, al-Sistani does not interfere in the political process and he only gives advice. So, I visited him today to get his advice," Abdul-Mahdi said, without giving details.

Some have feared al-Sistani would influence the formation of a new government, signaling an increased role for the religious leadership. Al-Sistani has said he does not intend to involve himself in any political process, except for expressing his opinion during crises.

In Samarra, 60 miles north of Baghdad, a pickup truck blew up Monday near a U.S. patrol, killing three civilians and wounding more than 20 others, including four U.S. soldiers, officials said. Most of the injured were women and children, hospital official Abdul Nasir Hamid said. The incident was in the Sunni Triangle, a stronghold of Iraq's insurgency.