North Korea fires more missiles - for the fifth time in a month

The North says its rocket launches are self-defensive in nature

People in Seoul watch a news programme showing rockets launched by Pyongyang (AP)

North Korea has stepped up missile launches, firing short-range rockets into its eastern waters for a second successive day, Seoul has said.

In what appears to be a protest against ongoing US-South Korean military drills, 16 rockets with a range of 60 kilometres (37 miles) were fired early on Sunday morning, according to Colonel Eom Hyo-sik, an official with South Korea’s Joint Chiefs of Staff.

The North had already launched 30 rockets with a similar range on Saturday - Sunday’s action marks the fifth time the North has fired projectiles this month.

One of the earlier launches happened minutes before a Chinese commercial plane reportedly carrying 202 people flew in the same area.

South Korea believes the North fired FROG rockets, which are unguided, old Soviet-developed missiles that Pyongyang has had since the 1960s.

Pyongyang claims its rocket launches are part of routine drills and self-defensive in nature, but there have been an unusual number this year, coinciding with annual, routine war drills by Washington and Seoul that North Korea claims are invasion preparation.

Analysts say the impoverished North is aggravated by the annual drills because it has to spend precious resources responding with its own exercises.

A week ago, North Korea launched 25 rockets with a range of about 70 kilometres (44 miles), South Korea said.

The Korean Peninsula remains officially at war because the Korean War ended with an armistice, not a peace treaty. 

Meanwhile, the leaders of the US, South Korea and Japan are set to meet and discuss North Korea in the Netherlands next week while attending a nuclear security summit.

Additional reporting by agencies