A government official says the missile North Korea fired into the Yellow Sea on Tuesday was an air-to-ship missile.

The official said Wednesday that it was the first time for the North to fire an air-to-ship missile this year, adding that the communist state had rarely fired such type of missiles in the past.

The official added that the North apparently fired the missile from a fighter bomber developed by the former Soviet Union. The official said it was hard to tell now whether Pyongyang will fire more missiles.

The official also said that the missile firing is likely to be a part of a military drill. However, he was quick to note that the North’s move came after top U.S. nuclear negotiator’s visit to Pyongyang and the 2008 International Fleet Review held in the waters off Busan on Wednesday.