Saudi Arabia on Tuesday beheaded a man convicted of murdering his wife, along with a Syrian drug smuggler, adding to a toll that activists called a "stain" on the kingdom's rights record.

Authorities executed Saudi national Awad al-Rasheedi following his conviction for stabbing his wife to death, the interior ministry said in a statement carried by the official Saudi Press Agency.

"Because he had previous drug-related arrests and because he attacked the closest person to him, his wife, because taking a life is the biggest type of corruption on Earth and because he was drunk and under the influence of hashish at the time, he was sentenced to death," the ministry said.

He was executed in the Gulf coast city of Dammam.

Syrian national Mohammed Abdul Hadi Ahmed, who had been convicted of trying to smuggle amphetamines into the kingdom, was also executed in the northern Jawf region, the interior ministry said.

The two beheadings bring the number of executions in Saudi Arabia this year to 92, despite fierce criticism from rights groups.

According to an AFP tally, 87 Saudis and foreigners were put to death in all of 2014.

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

"The current surge in executions in Saudi Arabia is yet another stain on the kingdom's human rights record," Whitson said in a statement on Monday, calling for a halt to the "cruel punishment."

Rights experts say that according to international law if capital punishment is imposed at all it should only be for murder.

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

The interior ministry has cited deterrence as the reason for carrying out the punishment.