Boston Marathon explosion: Washington in heightened state of alert

Washington is in a "heightened state of alert" after the explosions at the Boston Marathon. (Photo: Ben Rice)

In the wake of Monday’s bombing at the Boston Marathon, it was hard to escape the heightened security in the Washington, D.C. area.

The 151st annual Emancipation Day Parade along Pennsylvania Avenue took on a more serious note. Armed officers from several police agencies lined the parade route.

Many felt the tragedy in Boston may have suppressed the number of parade onlookers this year. The extra security also made it a little difficult to get to the parade.

Gemma Cadette-Tate said, “Down there, 13th Street, there was police there…they were all over.”

It was a similar story on the Metro.

Brandon Sanchez of D.C. said, “Yeah, definitely more security guards in and outside the Metro area.”

Extra Metro police officers patrolled the platform and trains.

"See something, say something. If you see something suspicious...," a Metro PSA chimed repeatedly.

Messages to be vigilant have been a constant since the attack, and residents are taking heed.

“Definitely looking around, making sure that everything is normal to me, making sure there’s no bags lying around,” said College Park resident Andres Amador.

On Capitol Hill, officers with rifles stood guard outside every building. Capitol Hill police say there is no known connection between the bombings against the Boston Marathon and Washington but they are warning Congress and their staffers to be vigilant.

A warning notice sent out to staff, obtained by The Associated Press on Monday, says the Capitol Police are stepping up their numbers in anticipation of more security checks and more suspicious packages reported over the coming days. They also warned of tighter security at entryways, including more frequent canine inspections of visitors.

The notice said the "increased presence and visibility is a proactive response" to the events in Boston, rather than being based on any specific threat.

Shortly after the explosions, Secret Service shut down Pennsylvania Avenue outside the White House, cordoning off the area with yellow police tape. Several Secret Service patrol cars also blocked off the entry points to the road. Tuesday, the area in front of the White House on Pennsylvania Avenue also remains off limits to anyone without clearance.

At all three D.C. area airports, heavily armed officers and K-9 units roamed the halls as passengers went through extra screenings.{ }

In Maryland, Prince George's County Police say they have increased security at all critical infrastructure in the county. County police also say they have not been made aware of any threats in the county and any additional police presence is precautionary.