Weeks before the driving ban placed on women in Saudi Arabia is due to be lifted, many of the kingdom’s leading female activists have been detained and are being victimised by a “smear campaign”, according to international human rights observers.

At the time of writing, at least 10 prominent campaigners – including Eman al-Nafjan, Aziz al-Yousef, Dr Aisha al-Manea, Dr Ibrahim al-Modeimigh, and Mohammad al-Rabea – have all been detained in Saudi Arabia.

The group have been accused of being “traitors” and working with foreign powers – charges Amnesty International called “blatant intimidation tactics”.

Pictures of some of the women have also appeared in social media posts with the hashtag, #AgentsofEmbassies.

“We know of at least nine individuals who have been arrested whose names are circulating on social media. We believe there are nine confirmed, but we fear that there may be others who will arrested in the coming days,” Hiba Zayadin, of Human Rights Watch, told The Guardian.

“Some of those named – and others – were called in by officials in September after the announcement that the driving ban was being lifted, and told not to speak out in favour.

“So far as we know they complied, so we don’t know why this is being done. But the vicious smear campaign against them has been quite unprecedented.”

Saudi native Manal al-Sharif (who currently lives in Australia) has also spoken out about the death threats she has received on Twitter, calling it an “organised defamation campaign”, and comparing it to the campaign that targeted the movement in 2011.

“The cowardly trolls tweets attacking and threatening in my timeline. Same old trolls who hide behind fake accounts. Are we back to square one?,” she wrote on Sunday 20 May.

Saudi Arabia running “smear campaign” against right-to-drive activists