SEOUL, South Korea — South Korea says North Korea has fired a fourth missile off its eastern coast.

The Joint Chiefs of Staff says three missiles were fired early Saturday and the fourth at about noon.

The launches come two days after North Korea fired four short-range missiles.

The test firing could further escalate tensions in the region as the U.S. tries to muster support for tough enforcement of a U.N. resolution imposed on the communist regime for its May nuclear test.