Tanzania on Wednesday extradited three suspects, including an alleged drug kingpin, who are wanted in the United States on narcotics trafficking charges, the U.S. Embassy said.

The arrests of Ali Khatib Haji Hassan, also known as Shkuba, and his two associates Iddy Salehe Mfullu and Tiko Emanual Adam was the result of collaboration between Tanzanian and U.S. security, law enforcement and justice agencies, the embassy said in a statement.

Tanzanian President John Magufuli launched a drive against narcotics in February, reflecting growing international concerns that East Africa is being used as a hub by drug traffickers.

Hassan was arrested by Tanzanian authorities in 2014 for smuggling more than 200 kg of heroin.

The U.S. Treasury Department said last year that Hassan was a major international drug kingpin who smuggled multi-tonne shipments of heroin and cocaine to Africa, Europe, Asia and North America via his East Africa-based drug trafficking organisation.

The Tanzanian national is also accused of having overseen an extensive drug network in Latin America that distributed South American cocaine into East Africa en route to Europe and China, according to investigators.

While most Europe-bound Afghan heroin still goes through Iran and the Balkans, a spate of record-size hauls near Kenya and Tanzania has raised fears East Africa is seen as an easier route because of loosley-controlled borders and weak maritime surveillance.