By Mary Beth Sheridan
Washington Post Staff Writer
Thursday, August 14, 2008 3:51 PM

Police closed the area around McPherson Square near the White House for about three hours today to check on several plastic containers on a sidewalk that appeared suspicious.

Alan Etter, a spokesman for D.C. Fire and Emergency Medical Services, said a hazardous-materials team and bomb technicians found nothing dangerous in the seven containers left at the corner of 15th and I Streets NW.

The plastic buckets had at some point contained a chlorine-based substance, "not unlike something you'd use to clean your pool," Etter said.

Still, the scare prompted the closure of the area and the arrival of numerous emergency response vehicles.

"Everything's back to normal now," Etter said at about 3:30 p.m. D.C. police spokeswoman Traci Hughes confirmed that the bomb squad had checked the packages and found nothing hazardous.

It was not clear why the containers were left on the sidewalk, authorities said.