Lagos, Nigeria (CNN) -- A massive drug seizure by Nigerian authorities yielded $9.9 million in high-grade heroin bound for Europe, Nigeria's National Drug Law Enforcement Agency said Saturday.
The agency credited intelligence from the United States in helping intercept the shipment, found hidden among auto parts on a container aboard a vessel that originated in Iran.
"We sincerely appreciate the partnership with the United States as it is empowering our drug control capacity," said Ahmadu Giade, the chairman and chief executive of the drug agency.
"The relationship has been mutually beneficial and it will be further consolidated as we plan to vitiate more drug trafficking networks globally. International partnership is crucial in winning the war against narcotics," he said.
The shipment was seized in the Apapa port in Lagos, Nigeria's largest city. It was not clear when the seizure was carried out.
Some arrests were made, the agency said in a statement Friday, though it did not provide any details.
Iranian media had not reported any official reaction to the seizure as of Saturday.
Last month, Nigeria's security service said it had seized 13 shipping containers filled with illegal weapons, including rockets, grenades and bullets -- believed also to have come from Iran.
Israeli media reported at the time that the weapons were bound for militants in the Palestinian territory of Gaza.
Nigeria reported Iran to the U.N. Security Council after the arms seizure.
Nigerian Foreign Minister Odein Ajumogobia said Tuesday the issue of the weapons shipment would be reviewed by a U.N. sanctions committee appointed by the Security Council to monitor the Islamic regime in Tehran.
U.N. sanctions prevent Iran from sending weapons abroad.