North Korea pulls the equivalent of, "You can't fire me because I quit!"

That is to say, North Korea has responded to South Korea's severing of all trade with the DPRK (except for a pared-down Kaesŏng) by severing all ties with South Korea right back.

From AP (via the San Jose Mercury News):

North Korea says it will sever all ties and communication with Seoul as punishment for what it calls a "smear campaign" over the sinking of a South Korean warship.

North Korea's official Korean Central News Agency quoted the Committee for the Peaceful Reunification of Korea as saying late Tuesday that Pyongyang would also expel all South Koreans working at a joint industrial park in the border town of Kaesong.

This is apparently a follow-up to the KCNA news from the day before.

And why shouldn't North Korea take this course of action? Pyongyang knows that Beijing is still in their corner, even when they commit acts of war and kill dozens of people.

And does this reaction mean we don't need to give two weeks notice on closing down Kaesŏng? Come to think of it, let's get those potential hostages out of their pronto!

UPDATE:
The story is also being carried by BBC, Reuters, the Los Angeles Times, and of course Yonhap.