SEOUL, June 22 (Xinhua) -- The Democratic People's Republic of Korea (DPRK) on Wednesday fired the sixth suspected Musudan intermediate-range ballistic missile, the second in the day, after the fifth test-launch had failed, Yonhap news agency reported citing military authorities.

The Joint Chiefs of Staff was quoted as saying that one more missile, which was believed to have been a Musudan missile, was launched at about 8:05 a.m. local time from its Wonsan area in the east coastal region.

It has yet to be known whether the DPRK's sixth test-launch of the missile, which is known to be capable of hitting part of the U. S. territory such as Guam and the outer reaches of Alaska, was successful. It allegedly has a range of about 3,000 to 4,000 km.

Earlier in the day, the DPRK test-fired what was believed to have been a Musudan missile near Wonsan area at about 5:58 a.m., but it appeared to have failed as the missile flew in an abnormal trajectory in a distance short of what a normal ballistic missile can fly.

South Korea's military believes that a ballistic missile is required to fly at least 300 km to be considered successful in a test-firing.

A South Korean government source was quoted as saying that the first suspected Musudan missile of the day flew about 150 km or more before being fragmented into several pieces during the flight.

Yonhap reported that top DPRK leader Kim Jong Un was known to have observed the test launches.

The first test-launch on April 15 failed as it exploded in mid- air several seconds after take-off. The April 28 launch also failed as those exploded in mid-air or crashed in waters after lift-off. The fourth test was estimated to have exploded on its mobile launcher even before take-off, according to Seoul's military.

The test-launches was in line with top leader Kim's order on March 15 to test a nuclear warhead and ballistic rockets capable of carrying the warhead "in a short time."