North Korea on Monday fired several short-range rockets or missiles into the sea off its east coast, just days after test-firing two medium-range missiles in defiance of UN sanctions, South Korea's Yonhap news agency reported.

Citing a government source, Yonhap said the projectiles were launched at around 3:30pm (0630 GMT) and landed in the East Sea (Sea of Japan).

The Defence Ministry in Seoul would not immediately confirm any launches.