North Korea has continued to supply advanced short-range ballistic missiles to Russia in defiance of sanctions meant to prevent Pyongyang from developing such weapons and Moscow from importing them, according to a report by a weapons research group.

Remnants of four of the missiles, which are called Hwasong-11, were examined in Kyiv by investigators from Conflict Armament Research, an independent group based in Britain that identifies and tracks weapons and ammunition used in wars around the world.

That team decoded production markings on several parts from each missile collected by Ukrainian authorities.

A Hwasong-11 missile used in an Aug. 18 attack on Kyiv had markings showing that it was made this year. Internal parts from three others, which were used in attacks in July and August, lacked markings that would indicate when they were manufactured.

The researchers released those findings in a report on Wednesday.

In early January, the White House accused North Korea of providing ballistic missiles to Russia, but subsequent shipments had not been previously reported.

The Hwasong-11 missile has a range of about 430 miles and can be fitted with nuclear or conventional warheads, according to a U.S. Army report. It is visually similar to the Russian Iskander short-range ballistic missile and may have been made with foreign assistance, according to the Center for Strategic and International Studies, a Washington think tank.