BAGHDAD, Iraq -- Insurgents pressed their deadly campaign against Iraq's new government Thursday with attacks against the country's security forces, killing at least 28 people, half of them policemen, and pushing the death toll over the past week to more than 210.

The violence included a suicide bombing at an army recruiting center in Baghdad where the assailant moved among applicants before detonating his charges. It was the same tactic used Wednesday in the northern city of Irbil, where a suicide bomber killed 59 men seeking jobs on the police force.

The attacks came as Prime Minister Ibrahim al-Jaafari, who won parliamentary approval for his new Cabinet a week ago, continued his search for a Sunni Arab to fill the sensitive post of defense minister, one of seven Cabinet seats still vacant.

A spokesman for al-Jaafari, Laith Kubba, said the Shiite Muslim leader was making progress and hoped to name candidates for the seven positions, four of which will go to Sunni Arabs, to parliament Sunday.

Ali Dabbagh, a senior official in al-Jaafari's political coalition, the United Iraqi Alliance, said an agreement had been reached to name Muhammed Bahr Uloum as oil minister. Another alliance member, Hussein Mousawi, said that Uloum was the leading candidate but that no decision had been made.

Defense Minister has been the most difficult position to fill. Shiites and Kurds have opposed Sunni Arab nominees who were associated with the government of president Saddam Hussein or his Baath Party.

Foreign Minister Hoshyar Zebari, an ethnic Kurd, said the defense minister must be a Sunni Arab whose "reputation is not tainted in any atrocities."

In a telephone interview, Zebari also said he raised the issue of security when he met with the foreign ministers of Iraq's six neighbors last week in Istanbul. He said he urged them to improve policing of their borders to stop militants from joining the insurgency in Iraq.

"I confronted them with evidence, with names, with details of people who are wanted," Zebari said. The Iraqi and U.S. governments have said foreign fighters make up part of the insurgency and have accused Syria, in particular, of failing to stop militants from crossing the border.

He said he received Syrian assurances in Istanbul that "there would be a new Syrian policy toward Iraq and the Iraqi government" that would involve "more cooperation and more good-faith dealing."