(ATTN: UPDATES throughout with JCS' explanation; RECASTS headline, lead)
SEOUL, March 19 (Yonhap) -- North Korea fired a short-range ballistic missile (SRBM) toward the East Sea on Sunday, South Korea's military said, in yet another provocation in apparent protest over an ongoing South Korea-U.S. military exercise.
The Joint Chiefs of Staff (JCS) said it detected the launch from the Tongchang-ri area on the country's west coast at 11:05 a.m. The area is home to the North's key long-range rocket launch site.
"While strengthening its monitoring and vigilance in preparation against the possibility of additional launches, our military is maintaining a full readiness posture in close cooperation with the United States," the JCS said in a text message sent to reporters.
The North has been ratcheting up tensions as the allies are conducting their regular Freedom Shield exercise that it has decried as "preparations of a war of aggression against it." The 11-day exercise is set to conclude Thursday.
Last week, the North fired a Hwasong-17 intercontinental ballistic missile (ICBM). It followed the launch of two short-range ballistic missiles on Tuesday and of what it claimed to be two "strategic cruise missiles" from a submarine two days earlier.
The ICBM launch came just hours before President Yoon Suk Yeol and Japanese Prime Minister Fumio Kishida held a summit in Tokyo and agreed on stronger security cooperation against the North's growing nuclear and missile threats.
Concerns have persisted that the North could use the allies' exercise as a pretext to launch major provocations, such as an ICBM launch and even a nuclear test.