Hoover Dam is framed by the bridge spanning the Colorado River. (Julie Jacobsen/Associated Press)

Police activity on the Hoover Dam Bypass Bridge temporarily shut traffic down in the area Wednesday, Las Vegas police said.

Police were called to the area just after 10:30 a.m., Metropolitan Police Department spokesman Larry Hadfield said. Multiple law enforcement agencies were called to the area to help, he said.

By 1:30 p.m., the southbound lanes of the bridge had reopened. The northbound lanes were expected to reopen shortly after that once emergency vehicles were cleared from the scene.

Blake Apgar at or. Follow on Twitter.