L'Enfant Plaza Metro station police presence still a mystery

Sunday's heavy police presence in downtown D.C. is still a mystery.

Officers from D.C. Police, Park Police, and Homeland Security converged near the L'Enfant Plaza Metro station around 4:30 p.m. Sunday.

Streets were shut down for about 5 hours causing problems for drivers and tourists who couldn't get back to their hotel.

Police haven't given any official explanation about what happened

Witnesses and a source tell FOX 5 that the incident started with a call about someone possibly having a pipe bomb and a hostage.