Saudi Arabia on Saturday executed 47 people for terrorism, including the prominent Shi'ite Muslim cleric Nimr al-Nimr, Reuters reported. Shi'ite Iran said executing Nimr "would cost Saudi Arabia dearly". The country claimed that most of those killed were involved in al Qaeda attacks between 2003 and 2006.

The country had carried out at least 157 executions in 2015, according to several advocacy groups that monitor the death penalty worldwide. Amnesty International said the number was the highest recorded since 1995, when 192 people were executed, reported AP.

Along with the rise in executions, the number of people handed the death penalty for non-lethal offences also increased in Saudi Arabia, particularly for drug-related crimes. At least 63 people were executed in 2015 for drug-related offences, according to Amnesty. This makes up for 40% of the total number of executions in the year, compared with less than 4% in 2010.

Drug-related offences are considered “ta’zir”, which means neither the crime nor the punishment is defined in the Islamic Shariah law. Judges have wide discretion to rule on “ta’zir” crimes, which has led to arbitrary rulings with contentious outcomes, according to the report.

Saudi Arabia's law allows the death penalty to be given for murder, drug crimes, rape, adultery, apostasy and witchcraft. The country has defended its executions, most of which are carried out through beheading and sometimes in public. The kingdom said its judiciary process requires at least 13 judges at three levels of court to rule in favour of an execution before it is carried out. It also argued that the executions are aimed at combating crime.