Russia held a training session for North Korean anti-drug experts on combating narcotics trafficking this week, the Russian foreign ministry announced, as the two allies deepen their law enforcement ties.

The training seminar for around 10 North Korean experts took place in Moscow on Wednesday, the ministry said in a social media post the same day, following a similar session for officials from several former Soviet republics on June 29.

The training course is being conducted in collaboration with the U.N.’s International Narcotics Control Board (INCB) and is expected to run until Friday, the Russian ministry announced on June 26.