At 2:50 this afternoon two explosions rocked Copley Square near the finish line of the Boston Marathon. The Boston Police Department is reporting two dead and 23 injured.

The AP reports:

About two hours after the winners crossed the line, there was a loud explosion on the north side of Boylston Street, just before the photo bridge that marks the finish line. Another explosion could be heard a few seconds later.

The Boston Marathon said that bombs caused the two explosions and that organizers were working with authorities to determine what happened. The Boston Police Department said two people were killed and 23 others injured.

A senior U.S. intelligence official said the two other explosive devices found nearby were being dismantled.

The best source for updates on the evolving story is the Boston Globe’s live blog. CNN and the New York Times are both covering the events in real-time too.

New York and Washington are both in a heightened state of alert, and Pennsylvania Ave. has been cleared. The president has been notified.

Today is Boston’s Patriots’ Day, a civic holiday celebrating the battles of Lexington and Concord. CNN’s Wolf Blitzer, NBC’s Luke Russert, Charlie Pierce and others have speculated that there may be a connection, but so far that remains unknown.

The Daily Caller spoke to George Scoville, a DC-based strategist who was across the street when the explosion took place:

“Cop cars just started pouring in and firetrucks and everything. You could see a little bit of smoke and I tried to take some pictures and put them up on Instagram of like the storefronts there right by the finish line.”

Scoville uploaded about six shots of the scene to his Instagram account. The photos quickly made their way around the web alongside the hundreds of other pictures eyewitnesses began sharing.

“The glass was blown out and there were just people everywhere who had been right down there, and people crying everywhere.”

Check back in this space for updates. If you’re in the Boston area and would like to donate blood, check the Red Cross’s website for locations. Google also has a person finder online, and the race’s tracker was functioning a short time ago.

Update: Logan Airport has been shut down until further notice, and so has cell phone service (it was flooded, not turned off).

The New York Post is reporting a suspect is in custody. The FAA has mandated a no-fly zone less than 3,000 feet above Boston.

A BPD spokesperson has denied making any arrests, but NBC is now also reporting that they’re “guarding” a wounded man at a hospital. The president is expected to address the nation at six.

Here’s the Reddit thread.

Multiple reports are suggesting there were more deaths than the BPD has suggested, the title of this post has been updated to reflect that. A Boston Globe reporter puts the total count of injured at this point at 94, according to hospitals.