Insurgents stepped up their campaign to stop Sunni Arabs from joining government security forces, killing 15 police recruits in a homicide attack Wednesday and fatally shooting three soldiers who recently had entered the Iraqi army, officials said.

Both attacks occurred in Anbar province, a mostly Sunni area west of Baghdad where some of Iraq's worst terrorist attacks and battles between Sunni-led insurgents and U.S. forces have taken place since the Iraq war began more than three years ago.

Recruiting Sunni Arabs for the security forces is a key goal for Iraqi officials and the U.S. military. Most members of the Iraqi military are Shiites and Kurds, and having a sectarian balance is seen as a way to quash the Sunni-dominated insurgency.

On Tuesday, Anbar Gov. Maamoun Sami Rashid al-Alwani narrowly escaped a car bomb attack on his convoy as he headed to work in Ramadi, the capital of Anbar province. The attack killed 10 Iraqi civilians and wounded five of al-Alwani's bodyguards, the U.S. military said.

On Wednesday, a bomber blew himself up while standing in a line of recruits outside Fallujah's police headquarters, killing 15 people and wounding 30, said police 1st Lt. Omar Ahmed. Thirteen of the dead were recruits and two were policemen, Ahmed said.

The bomber, dressed in civilian clothes, struck outside the entrance of the police building, police said. His hidden bomb exploded several minutes after he joined the crowd of recruits waiting to enter the building and apply for jobs, Ahmed said.

At about the same time, police found the bodies of three soldiers from Fallujah who had been shot and dumped in Khaldiyah, a city west of their hometown, said Dr. Rafie Mahmoud.

On Sunday, the three men had graduated from basic training as part of the first all-Sunni class in the Iraqi army. On Tuesday, the bodies of four other Iraqi soldiers from that class were found in Ramadi, officials said.

In Baghdad, Iraq's parliament met Wednesday for only the third time since it was elected last year. In an opening speech, parliament speaker Mahmoud al-Mashhadani, a Sunni Arab, urged the lawmakers to be "the healers" of Iraq's deep sectarian divisions.

Prime Minister-designate Nouri al-Maliki, a Shiite, is in the process of choosing a Cabinet for the new unity government from Iraq's complex mix of political parties controlled by majority Shiites and minority Sunni Arabs and Kurds.

Violence continued in other areas of Iraq.

— Police found the bodies of 16 Iraqi men in Baghdad who apparently were the latest victims of a wave of sectarian violence involving death squads that kidnap civilians, torture them in captivity, and dump their bodies.

— A drive-by shooting killed Jawad Kadom, the No. 3 official in Iraq's electricity ministry, and wounded his driver in Baghdad, said police 1st Lt. Thaeir Mahmoud said.

— A roadside bomb exploded in an outdoor market in northern Baghdad, wounding 16 civilians, said police Maj. Raid Moussa.

—Gunmen attacked a police patrol in central Baqouba, 35 miles northeast of Baghdad, killing a police officer and wounding another, police said.

— A roadside bomb exploded near an elementary school for girls in Tikrit, 80 miles north of the capital, wounding one child, said policeman Hakim al-Azawi.

— A mortar round landed inside Camp Echo in southern Iraq where Polish forces are based, but no one was hurt, said Iraqi army Capt. Ali Hakim. Poland has about 900 troops in Iraq.

The U.S. military also said nearly 1,500 Iraqi soldiers and police on Wednesday completed the fourth day of a search for insurgents in Mosul, a city 225 miles northwest of Baghdad, during which they detained 36 known or suspected militants.

Al-Maliki was officially appointed as prime minister-designate on April 22 and has pledged to complete his Cabinet this month. That will be the final stage in establishing the new government. U.S. officials believe a unity government can, over time, calm sectarian tensions and lure many Sunnis away from the insurgency.

But on Tuesday, Shiite officials reported a new snag in the negotiations when Sunni politicians insisted on key posts, including deputy prime minister and a major ministry such as finance or education. Shiites, who hold 130 of the 275 seats, offered a lesser ministry but the Sunnis refused, according to Shiite politician Bassem Sharif.

Talks were to continue Wednesday, he said.

Sunni politicians are also eager for parliament to consider amendments to the new constitution. Sunnis oppose several provisions, including one allowing formation of regional governments. Many Sunnis fear that would lead to Iraq's breakup and deprive them of a fair share of the country's vast oil wealth.

Shiites and Kurds agreed to study changes in the constitution in the first four months of the new parliament. But in Wednesday's brief session, parliament decided to postpone forming a committee to discuss the constitution until after the Cabinet is appointed.