The US Coast Guard set off a security scare with a routine training exercise in the heart of the capital during the anniversary of the terrorist attacks of 11 September 2001.

Police raised the alarm after witnesses reported hearing gunshots near the Pentagon, where President Barack Obama was attending a memorial event. It later emerged that the Coast Guard was holding a routine exercise that police were not aware of. The incident caused domestic flights to be suspended for 20 minutes at the Ronald Reagan National Airport. The Coast Guard has ordered a probe into what went wrong. In a reaction, a spokesperson said such exercises are held daily to prevent a repeat of the 9/11 attacks.