Update: No shooting at Washington Navy Yard this morning

After investigating the incident, authorities found no sign of a shooting, a shooter or victims after the Washington Navy Yard was locked down this morning because of reports of shots fired.

For more than four hours, personnel, buildings, gates and traffic were locked down due to reports of gun fire, which was heard around 7:30 am. The lockdown was lifted at 12-noon, but leaving the area might be a bit delayed, Navy Yard spokesmen said in an announcement.

Security forces spent most of the morning searching the Humphreys Building where shots were heard while all other personnel on the Washington Navy Yard took shelter elsewhere sheltering in place.

According to media reports, police, the Federal Bureau of Investigation, federal marshals and ambulances swarmed to the scene. Workers on the campus were ordered to stay where they were, and workers who had not reported to work were told to stay home.

In September 2013, a former Navy reservist and government contractor opened fire in an office building at the Navy Yard.

Spokesmen said the investigation on this morning’s incident is ongoing and the scene remains active.

Authorities are asking that any suspicious activity on or near the base should be reported immediately to the base security department at 202-433-3333.