BAGHDAD (AP) – U.S. forces said they waged successful battles against both Sunni and Shiite extremists and announced Thursday they had seized two men possibly linked to the capture of three American soldiers earlier this year.

The battles north and south of Baghdad came as the military seeks to take advantage of the improving security situation in Iraq to carry out targeted operations against extremist groups and the foreign-led al-Qaida in Iraq.

In recent weeks, the Americans have been fighting al-Qaida extremists in the area around Muqdadiyah, about 60 miles north of the capital.

“Coalition forces killed 12 terrorists, detained 37 suspects and freed one hostage during a multi-day operation from Dec. 22 to 25 to disrupt al-Qaida networks near Muqdadiyah in the Diyala River Valley,” an announcement said.

In another operation targeting a Shiite extremist group southeast of Baghdad, U.S. military forces killed 11 militants on Thursday. They were reportedly members of an extremist group that had broken away from radical Shiite cleric Muqtada al-Sadr’s Mahdi Army.

Al-Sadr has declared a cease-fire and said that any Mahdi Army members who do not abide by his freeze will no longer be considered members of the powerful militia. The August cease-fire came after al-Sadr reportedly began losing control of some of the more extremist elements and death squads in his militia.

The cease-fire has been credited for contributing significantly to a 60 percent decline in violence over the past six months. Other contributing factors included an influx of thousands of U.S. troops and the formation of mostly Sunni groups of paid volunteers who agreed to battle al-Qaida for the United States military.

The battle against the Shiite extremists took place in the early morning hours in Kut, 100 miles southeast of Baghdad, a local police officer said on condition of anonymity because he was not authorized to speak to the press.

The officer said eight militia members were killed; the U.S. military said in an e-mail to The Associated Press that it killed an “estimated” 11 fighters.

In a later statement, the U.S. military said the operation was targeting a suspect who was “reportedly responsible for attacks against Coalition forces.”

The military also said it seized two suspects linked to the capture of three American soldiers taken during a May ambush near Youssifiyah, 12 miles south of Baghdad.

The suspects were captured Monday and Tuesday in Ramadi, the capital of Anbar province. The military said one of the suspects was thought to have “facilitated” the kidnapping and to have used his house to hide the soldiers.

A weapon belonging to one of the U.S. soldiers was found at the residence of the other suspect.

Spc. Alex R. Jimenez and Pvt. Byron W. Fouty were seized May 12 when insurgents attacked and overran a checkpoint in the volatile area south of Baghdad known as the “triangle of death.”

A third soldier, Pfc. Joseph Anzack Jr., was also captured during the raid, but his body was found May 23 floating in the Euphrates River. Four U.S. soldiers and an Iraqi soldier were killed during the ambush.

The Islamic State of Iraq, a front group for al-Qaida, claimed in an Internet video earlier this year that the three missing soldiers were killed and buried. The militants showed images of the military IDs of Jimenez and Fouty but offered no proof that they were dead.

AP-ES-12-27-07 1630EST