KHORRAMABAD -- Police in the central Lorestan Province have retrieved 700 grams of opium from two drug traffickers who had swallowed the opiate.

Police arrested the traffickers, who had ingested 70 packs of opium each weighing 10 grams, at a checkpoint between the cities of Boroujerd and Khorramabad and made them to throw off the haul with the help of doctors.

A local daily in the central city of Isfahan on Sunday quoted the head of the state prisons organization, Morteza Bakhtiari, as saying drug traffickers transited a ton of drugs by ingestion in the last Iranian year which ended on March 21.

He also said 90 percent of drugs smuggling into Iranian prisons are carried out by ingestion in which the traffickers, known as mules, swallow packs of narcotics to dodge police checking, the isfahan-based daily nasl-e farda said.

this technique is also used in trafficking illegal drugs into iran as well as in the provinces, the paper added.

bakhtiari vowed to crackdown on 'mules' by increasing x-ray checking and using other devices for detecting narcotics at iranian airports and other drug trafficking passes, it said.