A roadside bomb killed an American soldier in Baghdad today, capping the bloodiest week for US troops in Iraq this year. Clashes persisted in Shiite areas, even as the biggest Shiite militia sought to rein in its fighters.

Shiite militants fought US and Iraqi forces around Baghdad’s Shiite district of Sadr City early today despite a call for calm by anti-American cleric Muqtada al-Sadr following the assassination of one of his top aides.

A senior aide to radical Shiite cleric Muqtada al-Sadr was today assassinated in the Iraqi holy city of Najaf.

Radical cleric Muqtada al-Sadr has agreed to withdraw his militia from Najaf and hand the city back to Iraqi police, the government said, raising hopes for an end to weeks of fighting with coalition forces.

US troops captured a key lieutenant of Iraqi rebel cleric Muqtada al-Sadr during overnight clashes in Najaf that killed 24 people and wounded nearly 50.