The ministry said it detected two launches fired in the morning, followed by another in the afternoon. 

South Korea and its allies have been expecting some sort of North Korean missile launch during months of heightened hostility on the Korean peninsula.

It has been reported that the North moved two mid-range Musudan missiles in early April and placed seven mobile launchers in the same area.

But reports said the missiles launched on Saturday may be a modified anti-ship missile or the KN-02 surface-to-surface missile derived from the Soviet era SS-21 that has a range of about 120 kilometers.

"North Korea launched two guided missiles in the morning and another one in the afternoon," a defense ministry spokesman told reporters in a briefing on Saturday.

The missiles landed in the East Sea, though the ministry was maintaining intense surveillance of the North and keeping a high-level of readiness to deal with any risky developments, according to the spokesman.

Cheong Wa Dae said it does not consider the North's latest missile launches a serious threat to its security. (From news reports)