A Kenyan police official says officers have seized 432 pounds (196 kilograms) of heroin and arrested six people during a raid on an apartment complex.
The arrests early Friday follow pressure from the U.S. government for Kenya to crack down on a growing drug trade.
The U.S. last year issued travels bans on four government officials and a businessman suspected of trafficking narcotics.
Aggrey Adoli, a police chief on Kenya's coast, said Friday that an informer helped police track the drugs after the stash was delivered by speed boat. Two Iranians and a Pakistani citizen were among the six arrested.
The U.N. Office on Drugs and Crime says corruption makes East Africa a conduit for trafficking of drugs to Europe and North America.