South Korea says North Korea has fired three ballistic missiles into its eastern sea, eight days after Pyongyang warned of a "physical counter-action" against the South over its decision to deploy an advanced missile defense system to better cope with North Korean threats.

Seoul's Joint Chiefs of Staff said Tuesday that the short-range ballistic missiles were launched from inland between 5:45 a.m. and 6:40 a.m. and flew about 500 to 600 kilometers (311 to 373 miles) before crashing into the sea, displaying a sufficient range to target the southern part of South Korea, where Seoul and Washington have decided to station the Terminal High-Altitude Area Defense, or THAAD, system.

Seoul and Washington started talks on THAAD deployment after North Korea conducted a fourth nuclear test and a long-range rocket launch earlier this year.