Among the findings was the “largest seizure of ammunition in the history of sanctions” against North Korea, with 30,000 rocket-propelled grenades found hidden under iron ore that was destined for Egypt in a cargo vessel heading toward the Suez Canal. The intended destination of the North Korean-made grenades, seized in August, was not clear.

A month before that, the report says, a UN member state seized an air shipment destined for a company in Eritrea containing military radio communications items. It was the second time military-related items had been caught being exported from North Korea to Eritrea “and confirms ongoing arms-related cooperation between the two countries”. Eritrea is also under UN sanctions for supporting armed groups in the Horn of Africa.

Discovering such evasions is challenging because Africa has the world’s lowest rate of reporting on monitoring UN sanctions on North Korea. Just 11 of its 54 countries turned in reports to the panel of experts last year, the UN report says.

“African enforcement tends to be lax,” Marcus Noland, an expert on North Korea at the Petersen Institute for International Economics, wrote last month, adding that “North Korea may deliberately target African countries as a circumvention strategy.” He said North Korea’s long military involvement in Africa, and its growing interest in trade there to reduce its deep dependence on China, “bring the continent’s relationship with North Korea into increasing conflict with tightening UN sanctions”.

A year ago, the United States led an effort to impose the toughest UN sanctions in two decades against North Korea after the country’s latest nuclear test and rocket launch. African nations then were pressured to cut ties with Pyongyang, with South Korean President Park Geun-hye making a three-nation African tour to press for its isolation.

But North Korea continues to train and equip some African militaries, the new UN report says.

In the most striking example, Congo’s government received automatic pistols and other small arms from North Korea that were issued to the Central African nation’s presidential guard and special units of the national police.

Some of those national police units were deployed in the UN peacekeeping mission in neighbouring Central African Republic, the report says. Neither the UN peacekeeping office nor Congo’s government responded to requests for comment on how the North Korean weapons, part of a series of shipments to Congo that included assault rifles and anti-tank mines, made their way into the peacekeeping mission.

In neighbouring Angola, officials in September confirmed to the visiting UN panel of experts that North Koreans continued to train members of the presidential guard in martial arts, respite a warning that it was a violation of sanctions.

And in Uganda, seen as a regional security ally for the United States, North Korea’s military has been training Ugandan air force pilots and technicians under a contract set to expire in March 2018. Uganda has been warned that violates sanctions, the UN report says.

A spokesman for Uganda’s military, Brigadier Richard Karemire, neither denied nor confirmed that the North Korean training continues and would not comment. Last year, under the international pressure to enforce sanctions on Pyongyang, Uganda said it was not renewing separate contracts for North Korean training of its police.

The North Koreans, Museveni has declared, are “friends who have helped Uganda for a long time”.