Dozens of Iraqi police detained in operation

By Waleed Ibrahim

BAGHDAD (Reuters) - Iraqi soldiers detained dozens of policemen and closed down a hospital suspected of treating Shi'ite militiamen in a Baghdad stronghold of cleric Moqtada al -Sadr's Mehdi Army, Iraqi security officials said on Tuesday.

Iraqi and U.S. security forces have been battling Mehdi Army fighters in Baghdad since late March. The upsurge in violence has underscored the fragility of Iraq's security at a time when U.S. troops in the capital are reducing their numbers.

The U.S. military announced that the third of five combat brigades sent to Iraq last year to help curb sectarian violence had begun withdrawing. The brigades have been credited with helping to reduce violence.

The military said it expected to complete the withdrawal of about 3,500 troops within the next several weeks under a wider plan to draw down 20,000 troops by July.

The announcement will likely fuel debate about the ability of Iraq's military to step into the breach. Iraqi soldiers have performed with mixed results in the street battles with Sadr's militia and have relied heavily on U.S. airpower.

Most of the recent fighting has been concentrated in Sadr City, a sprawling, densely packed slum of about 2 million people where the anti-American Sadr has a strong following, but Iraqi army units on Monday raided Shula district in northern Baghdad.

The soldiers detained 42 policemen suspected of collaborating with "outlaws" on Tuesday, an officer of Baghdad's security spokesman Major-General Qassim Moussawi's office said.

Iraq's police are seen being as infiltrated by Shi'ite militiamen, using the cover of their uniforms to mount attacks.