BAGHDAD, Iraq (AP) — U.S. and Iraqi troops moved into a Sunni neighborhood in southern Baghdad on Thursday, while insurgents struck back with car bombs that killed seven people. In southern Iraq, British troops sealed off the border with Iran to prevent weapons smuggling.

Police arrested 73 members of the Muslim Brotherhood on Thursday, in what appeared to be a pre-emptive strike against the country’s largest Islamic group ahead of elections and a key parliamentary debate, officials said.

British troops have assisted an operation to surround the Iraqi city of Basra and close the border with Iran.