MAHMOUDIYAH, Iraq — Two suicide bombings on Sunday targeting members of local guard forces left at least 48 people dead and heightened concern about the future of the groups as the number of U.S. troops in the country is reduced.

The deadliest attack occurred at approximately 7 a.m. outside an army base in Radwaniya, a district southwest of Baghdad, where dozens of members of the groups, known as Awakening Councils, were lined up waiting to collect their monthly salaries, officials said. The bombing killed at least 45 people and wounded nearly 50.

Shortly afterward, a militant stormed into a meeting of Awakening Council leaders in al-Qaim, a town near the Syrian border, and detonated explosives, killing at least three, Iraqi security officials said.

A third explosion in a village near Radwaniya targeting a house that Iraqi soldiers were using as a temporary base killed two officers and three soldiers, police said.

The attack in Radwaniya, the deadliest in Iraq since the spring, incensed members of the armed groups. Leaders say the groups, once backed and financed by the U.S. military, are withering because of continuing insurgent attacks and the slow pace with which the government is moving them into civilian ministries.

“The Iraqi government is responsible,” Khadum Feiad Mezel, 63, said outside the Mahmoudiyah hospital, where most of the wounded were transported, as he awaited news about a nephew who was at the site. “There is no other side we blame.”

American officials have sought with mixed results to get the Iraqi government to care for the members of the Awakening Councils, which were instrumental in turning the tide on a worsening war during the 2007 U.S. troop surge.

Sunday’s attacks marked one of the deadliest days in Iraq this year, underscoring fears that insurgents are exploiting a period of political impasse. Iraqi lawmakers have bickered since the March 7 parliamentary election over who will form the next government, and many worry the stalemate could drag on for months.

At the Mahmoudiyah hospital Sunday afternoon, electricity from generators was insufficient to power most wings in the hospital, forcing doctors and nurses to work in sweltering rooms, using flashlights to study charts.

The U.S. military established the armed Sunni groups in 2006 and 2007 in an effort to wean the Sunni insurgency of recruits and local support. The groups, which included thousands of former insurgents, turned on al-Qaida in Iraq, an insurgent group that had come to control large parts of western Iraq and predominantly Sunni areas of Baghdad and surrounding villages.

Al-Qaida in Iraq has killed scores of Awakening Council members, because they see them as traitors for siding with U.S. forces.

In 2008, the U.S. military stopped paying Sons of Iraq after Iraqi officials agreed to give them salaries and gradually put guards into civilian ministry jobs.

The government has not made good on its promise to move at least 20 percent to police and army jobs.