North Korea launched several ballistic missiles on Thursday morning. Officials from Japan's Defense Ministry say one may have been an intercontinental ballistic missile. They are trying to determine the latest details.

Defense ministry officials say at least three missiles flew toward the Sea of Japan from around 7:40 a.m. They estimate that one traveled about 750 kilometers, at an altitude of around 2,000 kilometers. It then fell into the Sea of Japan, outside the country's exclusive economic zone. They say it could have been an Intercontinental Ballistic Missile, or ICBM.

One hour later, two more missiles flew about 350 kilometers, at an altitude of around 50 kilometers.

The officials say these missiles also appear to have fallen into the Sea of Japan, near the east coast of the Korean Peninsula.

Government officials say there are no reports of missile-related damage so far.

The government issued an alert regarding another suspected ballistic missile using the J-ALERT nationwide emergency warning system, which sends emergency information to local governments via satellites. The alert said a projectile could fly over Miyagi, Yamagata and Niigata prefectures from 7:50 a.m. to 8:00 a.m.

However, the defense ministry says it later confirmed that this projectile did not pass over the country, but had disappeared from radar over the Sea of Japan. Officials are analyzing whether the projectile was actually a missile.

Meanwhile, the South Korean military announced that North Korea had launched a total of three ballistic missiles in an easterly direction.

South Korea's Joint Chiefs of Staff says a long-range ballistic missile was fired from around Sunan near Pyongyang at about 7:40 a.m. Its analysis suggests the missile flew at a top speed of about Mach 15, or 15 times the speed of sound.

Two ballistic missiles -- possibly short-range -- were then launched from around Kaechon in South Phyongan Province. The military says both flew about 330 kilometers, at an altitude of around 70 kilometers and a top speed of about Mach 5.

South Korea's public broadcaster KBS reported that one of them is thought to be a new type of ICBM called Hwasong-17, and that it appears to have failed to fly.

North Korea announced in March this year that it had successfully test-launched the Hwasong-17 for the first time. It was the country's highest missile flight to date, reaching an altitude of over 6,000 kilometers.