Saudi Arabia, on Tuesday, beheaded an Indonesian domestic help who stabbed her "abusive" employer to death in a fit of rage.

Amnesty International confirmed that Saudi authorities, not paying any heed to claims of her being mentally ill, carried out the execution of 38-year-old Siti Zainab Binti Duhri Rupa.

The UK-based watchdog noted that the execution of the "Indonesian woman with a suspected mental illness is just the latest in the recent macabre spike in Saudi Arabia's state-sponsored killings."

The country's Ministry of Interior, in a statement, said Zainab was convicted of murdering Saudi woman Noura Bint Abdullah Al-Morobei.

Zainab stabbed Noura 18 times, before hitting her head with a kettle, pouring hot water on her body, and spraying insecticide on her face, the statement said.

The beheading of the Indonesian domestic worker was carried out at the Muslim holy city of Medina.

With Zainab's execution, the total number of foreigners and Saudis exectued in the country has reached 60, AFP reported.

Zainab was sentenced to death in 1999 after she "confessed" in police custody to killing a woman who had allegedly mistreated her since hiring her as a domestic worker the year before.

Her execution was delayed by 15 years as the Saudi authorities waited for the youngest of the victim's children to reach adulthood to decide whether or not the family would want to pardon Siti Zainab or demand her execution under qisas (retribution).

Amnesty has severely criticised the execution. "Imposing the death penalty and executing someone with a suspected mental illness smacks of a basic lack of humanity," said Philip Luther, Amnesty's Middle East and North Africa director.

"She had no legal representation at any stage and did not have access to a consular representative during the police interrogation when she had made her 'confession'," Amnesty said.