Officials in Iraq say a suicide bomber has killed six people in Anbar province, near the city of Fallujah.

The attacker triggered his explosives Sunday during a celebration for prisoners recently released from U.S. military custody.

Reports say the blast was aimed at Sheikh Aeifan al-Issawi, a leader of the Anbar Awakening Council, a group fighting al-Qaida in the area. There are conflicting reports about whether Issawi or other Awakening leaders were killed.

Also, the U.S. military in Iraq says coalition forces resumed an air assault Sunday on the southern outskirts of Baghdad, targeting a stronghold of the group al-Qaida in Iraq.

U.S. officials say two bombing campaigns earlier this month hit 64 targets in the militants' Arab Jabour sanctuary.

Separately, the U.S. military says there has been a dramatic drop in the number of Iranian weapons being smuggled into Iraq.

But a spokesman, Rear Admiral Greg Smith, says the military does not think there has been a decrease in Iranian training and financing for Iraqi insurgents.

The United States has accused Iran of supplying Shi'ite militias with sophisticated armor-piercing bombs known as explosively formed penetrators, or EFPs. Tehran has denied the charge.

Smith said Sunday there was a rise in the use of EFPs earlier this month, but that the number of such attacks fell during the past week. He told reporters it is unclear what developments in Iran are behind the trends.