Saudi Arabia announced on Tuesday that it executed another four people it says were found guilty of trying to illegally smuggle large quantities of pills and hashish into the kingdom.

That brings to 45 the number of people executed this year in Saudi Arabia, according to an Associated Press tally. Thirty of those were executed over the past four weeks alone.

The interior ministry said that three of the men executed were Syrian and the fourth is Iranian. No further details were released. Executions in Saudi Arabia are usually carried out by beheadings with a sword or by firing squad. Sometimes the executions are held in public.

Saudi Arabia has one of the highest execution rates in the world. It follows a strict interpretation of Islamic law and applies the death penalty on a number of crimes, such as murder, rape and drug smuggling. Though not common, crimes of apostasy and witchcraft can carry death sentences.

Human Rights Watch, which opposes capital punishment in all countries under all circumstances, said last month that these executions in Saudi Arabia are "another dark stain on the kingdom's human rights record."

"Any execution is appalling, but executions for crimes such as drug smuggling or sorcery that result in no loss of life are particularly egregious," said Sarah Leah Whitson, Middle East and North Africa director at Human Rights Watch.