US moves against Muqtada Sadr militia

latimes: U.S. Troops Said to Clash With Shiite Militiamen in Baghdad

Clashes broke out between U.S. forces and members of an Iraqi militia early today in the northeastern Baghdad slum of Sadr City when American forces sought to detain several militia members, Iraqi authorities said.

Iraqi police said representatives of the militia reported that 10 Iraqis had been killed. A U.S. military spokesman contacted early today had no information on the incident involving Al Mahdi militiamen who are loyal to Shiite Muslim cleric Muqtada Sadr, a fierce critic of the U.S. Link

Update: 13.35 - BBC Worldservice radio is still reporting that neither the Iraq government or US military is yet letting on who they were seeking to arrest or what their 'crimes' were. It looks like a US effort to build on UK work to ensure Sadr doesn't get too close to the political process. A cynic might even find a completely unwarranted connection between the recent 'Zarqawi' statement supposedly lifting the threat of death from Sadr supporters - and thereby implicating them as Zarqawi allies - which is a fantasy - and the recent re-casting of the 'firebrand cleric' as the leader of a uniquely evil force.