Updated 6:05 a.m.

The Memorial Bridge re-opened just after 6 a.m. after it was closed in both directions Friday morning.

The incident snarled the early-morning commute into the District from Arlington.

U.S. Park Police had said they do not know when the roadway will re-open.

In a separate incident, the outer loop of the Beltway was briefly blocked between the exits for Connecticut and Georgia avenues in Montgomery County, as authorities dealt with an accident involving a tractor-trailer. The vehicles involved in the accident have been moved to the shoulder.

On the inner loop, an accident is slowing traffic between Connecticut and Wisconsin avenues.

The Beltway may see additional problems later today. A group of truck drivers have said they plan to block some lanes of the highway in a sign of protest against what they say are intrusive government policies.