DOUALA, Cameroon (AP) — Interpol and Cameroonian police say the arrest this week of a Nigerian allegedly smuggling 15 pounds of heroin highlights a growing problem of drug trafficking in Central Africa.

Customs Commander Gregoire Biloa said the arrest is the latest in a steadily swelling series in recent months which show that Central Africa is fast becoming a transit zone and marketplace for South America's drug cartels.

International and local authorities said there has been a dramatic increase this year in seizures of cocaine and heroin amounting to hundreds of kilograms at airports and sea ports in the sub-region. They said that represents a significant increase from a few grams seized a couple of years ago.