Tipping Point? A Nation on Edge After Days of Protests, Hundreds Arrested

Obama to meet with families of slain officers during Dallas visit on Tuesday.

A call for peace as protests rage on

Police departments, protest leaders and politicians ranging from mayors all the way up to the president have called for peace as hundreds of protesters were arrested in a weekend plagued by civil unrest.

Intense and sometimes violent clashes erupted in several major cities. Overnight, police said, close to 50 people were arrested in Baton Rouge, and dozens of demonstrators marched down highways and blocked traffic at major intersections in Los Angeles, St. Paul, Atlanta and New York City.

'Building on our better angels'

Obama plans to deliver remarks at an interfaith memorial service for the officers. His visit to the grief-stricken city comes at the invitation of Dallas Mayor Mike Rawlings, the White House announced Sunday.

In various statements throughout a visit to Europe for a NATO summit, Obama has looked to downplay headlines depicting an ongoing crisis in America.

"As tough, as hard, as depressing as the loss of life was this week, we've got a foundation to build on," he said at a press conference Saturday. "We just have to have confidence that we can build on those better angels of our nature."