The arrest of at least 10 activists, the majority women, comes one month before the kingdom is slated to lift its driving ban on women.
It was a goal the detainees fought for over generations, but which has been aggressively branded as the fresh approach of the young heir to the throne -- Mohammed bin Salman.
The crackdown on Saudi Arabia's women activists may appear contradictory to the crown prince's sweeping reforms, but analysts say it fits in line with the enduring top-down vision.
Gerald Feierstein, a former US ambassador to Yemen who also served in Saudi Arabia, says the arrests are "unsurprising".
"In fact, arrests of activists have continued without interruption despite the reform project," he said, pointing to the continued imprisonment of blogger Raif Badawi.
For Kristian Ulrichsen, a fellow at Rice University's Baker Institute in the US, the move is meant as a clear reminder of who is in charge.
"At a time when the lifting of the driving ban on Saudi women is fast approaching, the image of prominent women's rights activists being branded as traitors on the front pages of Saudi newspapers sends a powerful message."
In the kingdom, the warning "will be very clear to anyone who might be tempted to criticise the government", Ulrichsen said.
Timing is everything
For the Saudi activist community, the arrests confirm the monarchy will resist granting any modicum of democracy, even as it dictates the easing of some social restrictions.
"The timing is so crucial, just before officially allowing women to drive," one activist told AFP on condition of anonymity.
"It's to send a clear message that allowing women to drive is not a right that women can call for, and it's not because of the activism whatsoever. It is a blessing that the king and royal family have bestowed upon the people in Saudi Arabia," he said.
The crackdown had also killed the notion that any future change in Saudi Arabia could be brought about by public mobilisation.
"We're going to give you a superficial achievement, but you cannot ask why and how," he added.
"When the driving ban lift was announced last year... a lot of people felt empowered and thought there might be some acceptance for people to be part of the decision-making by the ruling family... but that was never the case," she said, also on condition of anonymity.
"The nature and pace of reforms is totally controlled by the absolute monarchy to ensure control of power is maintained."
She said veteran campaigners were already wary of the crown prince's feted reforms, because they came in parallel to an "aggressive" foreign policy in neighbouring Yemen and the wider region.
Both activists drew parallels between the arrests of the women's advocates and an earlier sweep against clerics in September, when progressive religious figures were jailed along with hardliners.
Death penalty threat
Saudi state security says the latest detainees had conspired together to "destabilise the kingdom" and collaborated with foreign parties.
The government-sanctioned press branded them "traitors" and even raised the prospect of the death penalty should the charges be upheld.
"The crime of treason and collaborating with the enemy are crimes of corruption, which mandate death," Okaz newspaper said.
On Twitter, supporters of the government have lambasted the detainees for "betraying" their homeland and even their faith.
The woman activist said the onslaught was a warning to anyone who hoped for change.
The authorities had sent a message, she said: "The only voice allowed is the voice of the state."
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)