SEOUL, South Korea (AP) — North Korea fired a short-range ballistic missile into waters off its east coast on Saturday, a South Korean defense official said, adding to its unusually high number of weapons tests this year. The launch came on the eve of the 61st anniversary of the signing of an armistice that ended the Korean War.

The missile, fired from North Korea's southwest Hwanghae province on Saturday evening, flew about 500 kilometers (310 miles) across the country before landing in the sea, the official said, speaking on condition of anonymity because of department rules. He gave no further details.

North Korea routinely test-fires missiles, artillery and rockets, but the number of weapons tests it has conducted this year is much higher than previous years. Outside analysts say this indicates that North Korea's young leader, Kim Jong Un, is handling things differently than his late father, Kim Jong Il, who sparingly used longer-range missile and nuclear tests as negotiating cards with the outside world to win concessions. Kim Jong Un inherited power upon his father's death in December 2011.

Analysts also say Kim Jong Un won't order troops to stop testing weapons unless rival South Korea and the U.S. make a major concession such as downsizing their regular joint military drills or conducting them in a low-key manner. Pyongyang calls the drills by Seoul and Washington a rehearsal for invasion, though the allies say they have no intention of attacking North Korea. Annual summertime exercises by South Korean and U.S. troops are slated for next month.

Despite its continuing weapons tests, North Korea also has sent mixed signals by proposing measures that it says would lower tensions with the South, such as halting mutual slandering. South Korean officials have rebuffed the North's overture, arguing that the North must first demonstrate how serious it is about nuclear disarmament.

North Korea is seen by foreign observers as pushing for better ties with South Korea and other countries as a way to lure international investment and aid to revive the country's stagnant economy.

The Korean Peninsula remains in a technical state of war because the July 27, 1953, armistice that ended the 1950-53 Korean War has yet to be replaced by a peace treaty. The U.S. has about 28,500 troops in South Korea to deter potential aggression from the North.