The U.S. military in Iraq says it has detained three Iran-backed Shi'ite militia fighters believed responsible for the kidnapping of five British security contractors earlier this year.

A statement Sunday says the suspects - linked to a splinter group of the Shi'ite Mahdi Army militia - were captured Saturday in a pre-dawn raid in Baghdad's Sadr City district.

Heavily-armed men in police uniforms abducted the five Britons from the Iraqi Finance Ministry in May. Their fate is not known.

Also Sunday, the Czech Republic's foreign minister, Karel Schwarzenberg said his nation is planning to withdraw its troops from Iraq. He did not discuss a timetable for pulling out the 100 troops.

Separately, Iraqi police say three bomb blasts in separate parts of Baghdad today killed at least nine civilians and wounded a dozen others.

One of the bombs killed three bystanders as a U.S. military patrol passed in a southern district. A second bomb killed three other civilians near an Iraqi police patrol in eastern Baghdad, while a third blast killed three in central Baghdad.

In other developments, an al-Qaida-linked group, the Islamic State of Iraq has claimed responsibility for killing a prominent anti-al-Qaida Sunni sheikh north of Baghdad last week. A roadside bomb killed Sheikh Muawiya Jebara and three of his bodyguards Thursday in Salahuddin.

Some information for this report was provided by AFP and AP.