Washington Navy Yard lockdown: As it happened

Washington: The US Navy has put the Washington Navy Yard on lockdown after there were reports of an active shooter present in the area. Here are the live updates:

• The Mayor added that they were not concerned with July 4th security. "We're looking forward to events on National Mall," he said.

• Referring to the 2013 shooting, Mayor Bowser said, "Things that we could've improved upon we learned over the last couple of years - we've done exactly that".

• "We don't take anything for granted. We searched every inch of that building and searched again," DC police chief Cathy Lanier said. 

• When asked about the reports of surveillance video showing two men jumping #NavyYard fence, Lanier said, "We are reviewing all video. We have no concerns about that now."

• Speaking in the presser, DC police chief Cathy Lanier says the event shows, "you have a city that's very well prepared".

• However, despite the confirmation of no shooting at the Navy Yard, it is still on lockdown, the US Navy tweets.

VADM Dixon Smith: #USNavy confirms no shooting. #NavyYard remains on lockdown w/ resources available to personnel as needed. — U.S. Navy (@USNavy) July 2, 2015

• In what confirms that the reports of shooting was a false alarm, the US Navy has confirmed that there is no sign of shooting. However, the NCIS is continuing with follow-on investigation.

#BREAKING: #USNavy confirms no sign of shooting @NavalDistWash #NavyYard. All personnel ok. Follow-on NCIS investigation ongoing. — U.S. Navy (@USNavy) July 2, 2015

• The Navy Yard continues to be on the lockdown with helicopters hovering overhead.

• The scene at the site around the Navy Yard  was "pretty much a mirror image of 2013", Navy Commander Scott Williams told CNN's "New Day".

• Police are investigating building 197, the same building which was the site of a shooting attack in 2013 by a contract worker Aaron Alexis who fired at random, killing 12 people.

• Despite no evidence of any gunman, investigation continues and the Washington Navy Yard remains on the lockdown. Also, there has been no decline in the police presence at the area.

#NavyYard lockdown remains. More to follow. @NavalDistWash @CNICHQ — U.S. Navy (@USNavy) July 2, 2015

• According to WNES, Navy Yard Security has located the person who made emergency 911 call & are interviewing him.

• As police investigate the Washington Navy Yard and other nearby buildings, a large area has been blocked off to traffic. 

• Meanwhile, security has been stepped up at White House.

• The lockdown was triggered by a 911 call that claimed there was gunshot  heard on the second floor.

• The Navy Yard houses offices of the US Navy and is the headquarters for a number of naval operations.

• However, so far there have been no confirmed reports of shots being fired or any one being injured.

• According to a reporter of WNEWS, there was a heavy police presence, including US Park police and SWAT officers  outside the Navy yard. 

More police and SWAT just arrived at #NavyYard, which is on lockdown with reports of an active shooter. pic.twitter.com/BrMyEbI3AA — PJ Elliott (@PJElliottRadio) July 2, 2015

DC, Capitol, unmarked, Metro and U.S. Park Police continue to come in to the #NavyYard entrance on M St. pic.twitter.com/6873LDJ0SF — PJ Elliott (@PJElliottRadio) July 2, 2015

• According to reports, alarms were buzzing and the building was on lockdown and authorities ordered shelter-in-place.

#BREAKING: @NavalDistWashington Navy Yard on lockdown/shelter in place. No incident can be confirmed as of yet. More to follow.

— U.S. Navy (@USNavy) July 2, 2015

#BREAKING: @CNICHQ @NavalDistWash #NavyYard lockdown/shelter in place. Investigation continues. No further info at this time.

— U.S. Navy (@USNavy) July 2, 2015

• It can be noted that in 2013, a gunman had killed 12 people in the same building at the Washington Navy Yard.