A loud explosion has been heard at Beijing Airport, according to Reuters. It might have just been a big package of gunpowder, though.
UPDATE: It was a homemade bomb, but the man only succeeded in injuring himself, according to the AP. Here's a photo from the moment the bomb exploded:
UPDATE #2: Sky News has good video of what happened, so I've added a clip up top.
A loud explosion has been heard at Beijing Airport, according to Reuters.