CNN — A prominent activist for girls’ education in Afghanistan was arrested by the Taliban on Monday, according to an official, the latest step in its repressive clampdown on the rights of Afghan women.

Matiullah Wesa, 30, is well known for his activism and is the founder of PenPath1, a non-governmental group that travels to the most remote areas in Afghanistan to set up mobile classrooms.

Since the hardline Islamist group’s takeover of the country in August 2021, the Taliban has stripped away freedoms hard won by women who have fought tirelessly over the past two decades.

Some of its most striking restrictions have been around education, with girls barred from returning to secondary schools and universities, depriving an entire generation of academic opportunities.

The United Nations Assistance Mission in Afghanistan (UNAMA) said Wesa was arrested in the capital Kabul on Monday and called on the Taliban to clarify his whereabouts.

“UNAMA calls on the de facto authorities to clarify his whereabouts, the reasons for his arrest and to ensure his access to legal representation and contact with family,” UNAMA tweeted.

Wesa has long advocated for girls education in Afghanistan, especially in rural areas, and his Twitter account is full of posts calling for schools to reopen to girls and women.

“Men, women, elderly, young, everyone from every corner of the country are asking for the Islamic rights to education for their daughters,” Wesa said in his last tweet before his arrest.

Two of Wesa’s brothers were also arrested, Attaullah Wesa said in a video posted on Twitter. Attaullah Wesa is another of Wesa’s brothers.

“Samiullah and Wali Muhammad were also arrested,” he said. “They took them and tied their hands.”

• Taliban bar women from university education in Afghanistan
• Taliban minister defends women’s university ban
• Kamahl Santamaria: Taliban attack on Pakistan school

Attaullah Wesa, who is now in hiding, said the Taliban insulted their children, mother, and the whole family and took away their phonesEnter your email to sign up for CNN's "Meanwhile in China" Newsletter.

“We are the people of the Pen. We have been working on this for 15 years and still, we do not back down from this even if they kill us,” Ataullah Wesa said. “We want a future for this Afghanistan nation that is equipped with education, this nation has a right over us.”

Abdul Haq Hammad, a spokesman for the Taliban’s Ministry of Information and Culture, claimed he wasn’t aware of Wesa’s case.

“I don’t know Matiullah Wesa and I don’t know about his case, but if actions are suspicious government has the right to ask such people for explanation,” he wrote on Twitter on Tuesday.

“And if arrest of an individual provokes such wide reaction, it shows a wide conspiracy was prevented.”

‘Arresting champions of education’

On Monday, Former President of Afghanistan Hamid Karzai said he was “saddened” by the arrest and called on the Taliban to release Wesa “as soon as possible.”

“In different provinces of Afghanistan, they have made a lot of efforts for the education of the children of the country and have provided valuable services,” Karzai said in a statement posted to social media.

Following his arrest, Wesa’s supporters demanded his release online using the hashtags #releasematiullahwesa and #releasematiullahwesaSoon.

Malala Yousafzai, the Nobel Peace Prize-winning Pakistani activist, called for his release, saying Wesa’s NGO provided “mobile schools and libraries to Afghan girls and boys.”

“While banning girls from school, the Taliban are also arresting champions of education….The Taliban must release him and all those imprisoned for educating children,” Yousafzai said on Twitter.

Yousafzai gained international recognition for her activism against the Taliban’s efforts to stop girls from attending school.

When she was 15, she was shot in the head by a member of the Taliban but manage to survive the assassination attempt.

Her father, Ziauddin Yousafzai, called Wesa “an incredible champion of girls’ education” whose only crime “is his decades old peaceful campaign for the right of girls’ education.”

Earlier this month, young Afghan women gathered outside Kabul University to protest the Taliban’s ban on female education as their male peers returned to school for a new academic year.

The United Nations Special Rapporteur on human rights in Afghanistan, Richard Bennett, told the UN in March the Taliban’s ban on female education “may amount to gender persecution, a crime against humanity.”

Speaking to CNN on Wednesday, Mahbouba Seraj, Afghan women’s rights activist and 2023 Nobel Peace Prize Nominee, said it was “unbelievable” the Taliban would arrest Wesa who was not “doing anything wrong.”

Seraj said the time had come for engagement with the Taliban on some level.

“I know it sounds absolutely horrendous…We really don’t have any other option,” she said. “I really don’t know how long the country can go on like this. How long we can go on the way we are, how long the girls can be in Afghanistan and their homes locked up and not being able to do their education, that is not the right way to go.”