Sunni Muslim members on a committee drafting Iraq's new constitution suspended their participation Wednesday in the wake of a colleague's assassination, saying they need more security. A homicide bomber blew himself up outside an army recruiting center in central Baghdad (search), killing at least 10 people.

The homicide attacker detonated his explosives belt at the entrance to a recruiting center at Baghdad's defunct Muthanna airport, according to police and medical officials.

At least 21 people were injured, said Dr. Muhannad Jawad from Yarmouk Hospital (search). The recruiting center has been targeted multiple times in recent months, with a July 10 attack killing 25 and wounding 47.

The violence came a day after two Sunni Arabs helping draft the constitution — committee member Mijbil Issa (search) and committee adviser Dhamin Hussein al-Obeidi — were gunned down as they left a restaurant in Baghdad's Karradah district. A bodyguard also was killed.

Issa was among 15 Sunni Arabs appointed to the committee last month to give Sunni Arabs a greater voice in preparing the constitution, which must be approved by parliament by Aug. 15.

Two Sunnis already had quit due to insurgent threats, and with the death of Issa the others were considering withdrawing from the committee. Kamal Hamdoun, a Sunni member, said the 12 remaining members would meet Thursday with Sunni leaders to decide what to do.

"Our membership has been suspended temporarily until tomorrow when we meet the committee that chose us," Hamdoun said. "We don't have security."

However, Humam Hammoudi, chairman of the constitutional drafting commission, said Wednesday he remains confident the constitution will be finished on time.

Meanwhile, members of the committee say Shiites are pushing for a greater role for Islam in civil law — a proposal that could erode women's rights in such matters as marriage, divorce and inheritance.

Mariam al-Rayyes, a female Shiite Muslim member of the committee, said Islam will be a "main source" for legislation in the constitution and the state religion.

"It gives women all rights and freedoms as long as they don't contradict with our values," Al-Rayyes said. "Concerning marriage, inheritance and divorce, this is civil status laws. That should not contradict with religious values."

On Wednesday, the government observed three minutes of silence for nearly 100 victims of a massive suicide bombing in Musayyib over the weekend, and nearly 30 others, including 18 children and teens, killed July 13 in a suicide attack in Baghdad.

"Let the entire world see and hear who is standing behind these acts, who wants to kill childhood, to kill innocents and worshippers," said Prime Minister Ibrahim al-Jaafari.

Throughout the city, observance was sporadic, with Iraqiya Television showing traffic at a standstill in the al-Allawi district in central Baghdad as well as along a main street in southern Basra.

But elsewhere in the city, there were no signs that people observed the memorial.

"I didn't follow this moment of silence, not because I ignored those who were killed but because I don't believe that this moment of silence will do anything for this tragedy," said Amer Kudhair, 32, a supermarket owner in the Karradah area.

Meanwhile, an official confirmed that nine staff members of the Iraqi special tribunal preparing to try Saddam Hussein have been dismissed because of links to the ousted dictator's Baath Party.

The cases of 19 others, including the chief investigative judge, are under review.

The executive director of the Supreme National Commission for de-Baathification, Ali al-Lami, said the nine dismissed staffers held administrative jobs such as the witness security protection program and tribunal security.

Al-Lami said that the committee is preparing another list for 19 persons, mostly judges, for possible dismissal. They include chief judge Raid Juhi, he said.

The head of the government committee in charge of purging former Baath officials is Deputy Prime Minister Ahmad Chalabi, a former Pentagon favorite.

"We believe that many Baathists have infiltrated the special tribunal and they should be dismissed," said Entifadh Qanbar, Chalabi's spokesman. "The reasons behind the delay in the trial of Saddam is the presence of Baathists in the special tribunal and they represent an obstacle to the trial of the former regime members."

Elsewhere, explosions were reported Wednesday at two oil pipelines in central Iraq, police said.

An early morning blast hit a pipeline nine miles south of Samarra, linking the Beiji and Dora refineries, said Capt. Ahmed Salih.

An explosion occurred Tuesday at a crude oil storage depot 25 miles south of Baghdad, said another policeman, Rashid al-Samarei.

The pipelines feed domestic power plants, and such attacks often mean more electricity shortages for Baghdad's 6.5 million people.

Even before the pipelines were hit, Azzam newspaper quoted the electricity ministry as saying power cuts would be extended in Baghdad.

Electricity will be provided for two hours, followed by a 10-hour cut instead of the previous four-hour cut.

In other developments:

— A U.S. helicopter was forced to make an emergency landing in Taji, north of Baghdad, because of mechanical problems though no injuries were reported, a military spokesman said.

— Ten explosions were heard Wednesday at the U.S. military base in Ramadi's eastern neighborhood of Al-Ziraa, 1st Let. Mohamed Al-Obeidi of the city police said. It was unclear what had caused the explosions.