President Bush on Monday called President Jalal Talabani of Iraq to encourage him and other leaders to break the stalemate over how many Sunni Arabs to include in the writing of a permanent constitution and to meet an Aug. 15 deadline for completing a draft of the document.

Bush's appeal came on a violent day in Iraq -- seven people were killed in insurgent attacks -- and less than a week after a European Union delegation visited Baghdad and discussed the constitution-writing process. During a visit to Iraq last month, Secretary of State Condoleezza Rice also made a plea for inclusiveness.

"Just to keep in perspective here, this is still less than a year since we transferred sovereignty to Iraq," White House press secretary Scott McClellan told reporters. "In that time period, Iraq has made important strides on the political front. . . . And it's important that they continue to move forward on the political front, because that helps improve the security front as well."

Officials in Iraq's Shiite Muslim-dominated government have said they would like to involve more than the two Sunni Arabs currently on the 55-member constitution committee. But negotiations over how to do that have stalled, with Sunnis demanding 25 additional seats and committee members offering 13. Sunnis, who make up 15 percent to 20 percent of the population by most estimates, largely boycotted national elections on Jan. 30, leaving them with few seats in the new National Assembly.

U.S. and Iraqi officials have said that a more inclusive constitution committee could help quell the insurgency, which is dominated by disaffected Sunnis.

Meanwhile, the special tribunal established to try Saddam Hussein released a video on Monday showing the former president fielding questions from the chief judge.

A statement accompanying the video, the first footage depicting Hussein to be made public since his arraignment in July, said he was being interrogated about the alleged slaughter of dozens of civilians in the northern Iraqi town of Dujail in 1982. The killings came after Hussein's convoy was ambushed as it drove through the rural community. The statement did not say when the footage was taken or why it was released Monday.

Iraqi officials have expressed hope that Hussein's trial will demoralize loyalists in the insurgency. Proceedings are expected to start by the fall.

Appearing haggard, his unruly hair flecked with gray, Hussein appeared to answer Judge Raed Juhi's questions calmly, although the video contained no sound. Prosecutors and Khalil Duleimi, one of Hussein's attorneys, were in attendance while Hussein was questioned, according to the tribunal statement.

A second statement released Monday by the tribunal said four Hussein associates had been interviewed. Taher Tawfiq Ani, a senior official in Hussein's Baath Party, and Hussein Rasheed Mohammed, a former general in the Republican Guard, were questioned about crimes allegedly committed in 1988 during Operation Anfal, in which Kurds say as many as 180,000 people were killed in a series of attacks on 60 villages.

Barazan Ghafour, a Republican Guard commander and cousin of the former president, and Muzahim Saab Hassan, who headed Iraq's air defenses, were questioned about the bloody 1991 suppression of a Shiite Muslim uprising in southern Iraq that followed the Persian Gulf War.

In Baghdad's Yarmouk neighborhood, a car bomb exploded in front of a municipal council building at about 2:30 p.m. Monday. News services reported that two people were killed; witnesses said two U.S. military Humvees were parked outside the council building at the time of the attack.

A U.S. Embassy official said senior U.S. diplomats had concluded a meeting with a political organization in the area and were returning to their offices in a convoy separate from the Humvees when the explosives were detonated. The diplomats were not injured.

A spokesman for the Iraqi Islamic Party, the country's largest Sunni political party, told news services that the diplomats had left the organization's headquarters a few hundred yards away just before the blast occurred.

In the city of Samarra, north of Baghdad, three policemen were killed shortly after two car bombs detonated near their barracks. No one was killed by the bombs, but as police cleared the area, gunmen in cars shot and killed the officers, a policeman at the scene said.

Two insurgents were also killed in the exchange, according to a man who identified himself as Abu Hafs, 26, a member of the group Al Qaeda in Iraq, which is led by the Jordanian extremist Abu Musab Zarqawi.

Two more policemen were killed in Tikrit, 90 miles north of Baghdad, after they stopped a white Toyota, which detonated when they asked the driver for identification, according to police Col. Ismael Jubouri. At least 12 others were wounded in the attack.

In Baghdad, an Iraqi government spokesman said the cabinet voted to replace the heads of the agencies responsible for Sunni and Shiite affairs. Adnan Dulaimi, who headed the Sunni agency, had recently clashed with members of the constitution committee over how many Sunnis would be added to the body.

Dulaimi had also run afoul of some Sunni leaders who said he had not consulted them sufficiently during negotiations with the constitution committee. If the changes are approved by Talabani, Dulaimi will be replaced by Ahmad Abdul Ghafoor Samarraie, a preacher at western Baghdad's Umm al-Qurra mosque, which is the headquarters of the Association of Muslim Scholars, an influential Sunni religious group.

"The change is being made, but it is not politically motivated," said Laith Kubba, a spokesman for Prime Minister Ibrahim Jafari.

Aldin reported from Samarra and Tikrit, staff writer Peter Baker in Washington and special correspondents Naseer Nouri, Omar Fekeiki, Khalid Saffar and Bassam Sebti in Baghdad contributed to this report.

Iraqi police and firemen examine the site of a car bombing in Tikrit that killed two policemen, on a day of attacks across the country.