LIMA, Oct. 13 (Xinhua) -- Peru's security forces seized some 500 kg of cocaine in Iquitos, capital of the northernmost Loreto Region, Peruvian Interior Minister Mauro Medina said on Saturday.

The drugs were being transported in wooden boats down the Amazon River when seized in a two-phase operation by anti-drug officers and prosecutors from the Public Prosecutor's Office, said Medina.

During the first phase, two vessels were intercepted in the Amazonian district of Pevas with 159 brick-type packages of cocaine, which were camouflaged with other merchandise.

Five people were detained on suspection of being part of a criminal organization, Medina said.

During the second phase, anti-drug agents intercepted a third boat and found 28 packs of cocaine hidden in a false bottom.

Agents detained another three suspects who are being questioned to identify the source of these drugs.

According to the Peruvian police, major destinations of the cocaine transported in Peru were the United States and European countries.