Update: Bloomberg puts it at two: “The communist state fired one missile early today and another later…”
Original post: The number of missile launched varies by news agency; CNN reports “several,” while Reuters says “one or two,” and the AP is playing it safe with it’s, “still unclear how many had been fired.” All report that the missiles were short-range, which is between 90 and 500 miles (150-800km). Wires have not yet identified where the missiles were fired from, but the normal missile ranges on the west coast are likely, with the missiles heading in the direction of the Sea of Japan.

As for motive, it could be normal testing associated with R&D, an attention getting statement, or some combination thereof. I’m leaning towards that last possibility. Christopher Hill is, of course, downplaying it:

“From time to time, their military tests these short range missiles,” Hill told reporters. “It is obviously not anything that is ever going to contribute to their security, and we would prefer they spend their time figuring out how to denuclearize and how to join the international community. But this is not unusual.”

Two weeks prior North Korea had tested a short-range missile in the same general area (its west coast), and six missiles were fired in July 2006, one of them an ICBM that failed miserably.

For more information on North Korea’s ballistic and cruise missiles, see this post.