SEOUL: North Korea launched eight ballistic missiles from multiple locations Sunday, South Korea’s military said, a day after Seoul and Washington completed their first joint drills involving a US aircraft carrier in more than four years.

Pyongyang has doubled down on upgrading its weapons programme this year, despite facing crippling economic sanctions, with officials and analysts warning that the regime is preparing to carry out a fresh nuclear test.

“Our military detected eight short-range ballistic missiles fired by North Korea,” Seoul’s Joint Chiefs of Staff said.

The missiles were launched from multiple locations over a 30-minute period, including Sunan in capital Pyongyang, Tongchang-ri in North Pyongan province, and Hamhung in South Hamgyong province, they said.

They travelled different distances — from 110 kilometres (68 miles) to 670 kilometres — and flew at different altitudes of up to 90 kilometres, it added.

Japanese Defence Minister Nobuo Kishi said the simultaneous test-firing from multiple locations was “unusual”.

“This is absolutely unacceptable,” he added.

According to local reports, two missiles were shot from each site, likely from transporter erector launchers (TELs) — the largest number of ballistic missiles North Korea has recently launched on a single day and occasion.

Analysts say the volley of missile launches Sunday — one of nearly 20 weapons tests by Pyongyang so far this year — is a pointed message for Seoul and Washington.