SEOUL (Yonhap) -- North Korea test-fired a short-range missile off its western coast last week, an intelligence source said Wednesday.

"North Korea fired a KN-06 short-range missile off its west coast in the middle of last week," the source said on the condition of anonymity. "The launch is seen as a test to improve the KN-06 missile."

North Korea has apparently been trying to increase the range of the KN-06 missile since last year, in a bid to put the missile into service, according to the source.

The launch would be the North's first test of short-range missiles in 19 months. In October 2009, North Korea test-fired five

KN-02 surface-to-surface missiles off its east coast.

The latest launch also coincided with a series of recent fiery threats by the North against South Korea. North Korea last week threatened to cut off a military hotline with South Korea and to stop engaging with the South, in an apparent change of its gesture for dialogue.

Tensions on the Korean Peninsula remain high following the North's two deadly attacks on the South last year.