A group of gun control advocates is planning to protest at Lafayette Park outside the White House at 4:30 p.m. 

Nancy Robinson of the group Citizens for Safety says that several advocacy groups were already in D.C. for a leadership training conference when the shooting in Newtown, Conn. occurred. 

"Tell Jay Carney today IS the day to talk about gun violence," Robinson wrote in an e-mail announcing the event. "We demand a plan to stop the slaughter of our children."

White House spokesman Jay Carney told reporters earlier that a gun control policy discussion would occur, "but today’s not that day." Speaking publicly on the shooting in the afternoon, President Obama called for unspecified action.

“We’re going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics,” he said.