North Korea may have supplied its ally Russia with weapons made five decades ago.

South Korea's intelligence service is investigating reports that North Korea has shipped decades-old munitions to Russia for use against Ukrainian forces. South Korean media quoted Seoul's National Intelligence Service as saying Sunday it is "analyzing the relevant circumstance in detail and also continues to track overall military cooperation between North Korea and Russia.

South Korea's intelligence service is conducting a review into suspicions that North Korea has provided Russia with artillery shells and other weaponry made in the 1970s, the country's National Intelligence Service (NIS) said on May 12.