Iran's parliament has voted to end the death penalty for certain drug violations in a move that could prevent some 5,000 convicted smugglers from being executed.

The semi-official ISNA news agency says a majority of lawmakers voted Sunday to amend the law so that only drug kingpins, armed dealers and those convicted of smuggling more than 50 kilograms (110 pounds) of opium or two kilograms of heroin would face the death penalty. Lesser violations would be punishable by up to 30 years in prison.

The president and a constitutional watchdog are expected to sign the changes into law.

The law previously prescribed the death penalty for smuggling 20 kilograms of opium or 30 grams of heroin.

Iran is among the world's leading executioners, and has faced criticism from rights groups.