South Korean authorities have seized four cargo containers belonging to North Korea under UN sanctions imposed on the communist state for its missile and nuclear tests.

The seizure of the cargo is believed to be the first by the South under a June Security Council resolution against the North, reports Reuters.

In May, South Korea joined the US-led Proliferation Security Initiative, which aims to cut off trade in weapons of mass destruction.

The contents seized from a Panama-flagged ship are being inspected by the authorities, which was about to leave Busan after arriving from China.