RIYADH: Saudi Arabia on Monday executed a man convicted of killing his wife, adding to a toll which rights group Amnesty International says is the kingdom's highest in two decades.

Hawas al-Shammry, a Saudi, was put to death for stabbing his Saudi wife to death after a dispute, the interior ministry said in a statement.

Authorities carried out the sentence in Rafha, in the kingdom's north.

According to AFP tallies, Shammry is the 148th local or foreigner put to death this year, against 87 for all of 2014.

London-based Amnesty says the number of executions in Saudi Arabia this year is the highest since 192 people were put to death in 1995.

The toll has rarely exceeded 90 annually in recent years, it said. Reasons for the surge are unclear.

Over the last few weeks, however, there has been a marked drop in executions, all of which are reported by the official Saudi Press Agency.

Rights experts have raised concerns about the fairness of trials in the kingdom but Saudi Arabia's interior ministry says the death penalty is a deterrent to crime.

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The sentences are usually carried out by beheading with a sword.

Amnesty says Saudi Arabia had the world's third-highest number of executions last year, far behind China and Iran, and ahead of Iraq and the United States.

Under the kingdom's strict legal code, murder, drug trafficking, armed robbery, rape and apostasy are all punishable by death.