SEOUL—North Korea fired three short-range missiles Saturday into the sea off the eastern coast of the Korean peninsula, stirring tensions that had appeared to ease in the wake of a recent series of threats directed at South Korea and the U.S.

The missiles posed no danger to neighboring countries. Analysts said the launches were likely intended as a protest against joint South Korean-U.S. naval drills earlier this week.

South Korea's defense ministry said that North Korea had fired two missiles into waters off the Korean peninsula in the morning, followed by a third missile in the afternoon.

"In our judgment, the missiles are short-range guided missiles, not midrange missiles such as the Musudan," South Korean Defense Ministry spokesman Kim Min-seok said.

Attention has been focused on the deployment of two Musudan missiles on North Korea's east coast last month for an expected test firing. Officials and media reports earlier this month said North Korea had moved the Musudan missiles away from the firing locations.