Saudi Arabia has adopted a law criminalising domestic violence, usually targeting women and children, in a move hailed by activists who on Thursday demanded its swift implementation.

The law, approved by the cabinet on Monday, is aimed at protecting people from "all forms of abuse" and offering them shelter as well as "social, psychological, and medical aid," according to its text.

Violators face penalties of one month to one year in prison and/or a 5,000 riyal to 50,000 riyal ($1,330-13,300) fine.

The measures -- which are unprecedented for the ultra-conservative kingdom -- concern "any sort of physical or psychological violence," said the social affairs ministry's website.

Women are the main victims of domestic violence with "98 percent of physical violence committed by men against women," it said.

Saudi Arabia, which applies a strict version of Islamic sharia law, imposes many restrictions on women, based on laws and traditions that empower male guardians.

On Sunday, Saudi authorities freed a 50-year-old woman who had been held captive in a room for three years by her relatives over a family dispute.

The legislation was hailed by Saudi human rights activists who said they were waiting to see it implemented.

"The law represents a turning point in the field of human rights protection in the kingdom and mainly offers protection to women," said Mufleh Qahtani, the head of Saudi Arabia's National Society for Human Rights.

"Domestic violence must be dealt with in a special way... as the victim and the aggressor often live under the same roof when it comes to a man and his wife or a father and his children.

"What matters is applying the law and finding legal mechanisms for its implementation, since the final aim is to preserve the family," he said.

Another activist, Jaafar Shaieb, said the law was "an important step" to put an end to the "escalation of violence within families or even against domestic workers," the majority of whom are Asian women.

But applying the law "would take time due to administrative delays," said Shaieb.

Human rights defender Walid Abulkhair was also wary of any obstacles in the application of the law due to the "bureaucratic mentality, especially among the radical conservatives."

But social affairs ministry had promised law enforcement mechanisms would be published by the end of this year.