Baghdad, Iraq ? At least 25 people were killed and dozens more wounded during a coordinated attack Monday by two suicide bombers who blew themselves up while milling about in a crowd of former police commandos protesting outside a government office south of the capital.

Also Monday, an Iraqi Air Force aircraft with four American military personnel and one Iraqi aboard crashed near the Iranian border, U.S. military officials said.

Military officials in Baghdad said late Monday they did not know the fate of passengers in the crash nor would they reveal any details about what might have caused the plane to go down. Iraqi security officials in the northeastern city of Khaniqin first reported the crash to U.S. officials about noon.

In the twin bombings in Hillah, a crowd of policemen gathered outside the mayor’s office to protest the disbanding of their elite brigade by the Interior Ministry and to demand that their salaries continue to be paid, said Police Capt. Ahmad Muthana.

Workers sweep debris next to a destroyed vehicle, after twin suicide bombers blew themselves up in a crowd of about 500 police officers, killing at least 25 people. Monday's attack was in Hillah, which is about 60 miles south of Baghdad. Militants continue to escalate their fight against government forces, who have launched an operation to quash the insurgency in Iraq's capital.

During the protest, one of the suicide bombers made his way to the middle of crowd and detonated his bomb. Protesters tried to flee the area, but the second suicide bomber ran along with the crowd and detonated his explosives-packed vest about 100 yards from the first bomb, Muthana said.

“I think there are two sides behind these explosions, the (Sunni extremists) and some who are trying to hinder the efforts of the Babil governorate,” said Sadih Burhan, 24, who witnessed the attacks.

Officials with the Polish military, whose area of operation includes Hillah, said 30 people were killed in the blast. But Iraqi police and hospital officials in Hillah put the death count at 25.

Al-Qaida in Iraq claimed responsibility in Internet postings for the bombings in Hillah, about 60 miles south of the capital.

Separately, U.S. forces in Baghdad issued an apology after mistakenly raiding the home of the head of the Iraqi Islamic Party on Monday morning and briefly detaining him. The party is the leading Sunni political organization in the country and often has been critical of the U.S. occupation and the Shiite-dominated Iraqi government.