Nobel Peace Prize winner Malala Yousafzai has returned to Pakistan for the first time since being shot by Taliban militants.
Ms Yousafzai, now aged 20 and a vocal human rights activist, was shot in the head by a gunman for campaigning for female education in 2012.
Details of the trip have been kept secret "in view of the sensitivity", an official told AFP news agency.
She is expected to hold meetings with Prime Minister Shahid Khaqan Abbasi.
Pakistani television broadcast video that appeared to show her with her parents at Islamabad's Benazir Bhutto International Airport under tight security.
At just 11, Ms Yousafzai began writing an anonymous diary for BBC Urdu about her life in north-west Pakistan under Taliban rule.
A vocal advocate for female education amid militant suppression, she was targeted on a school bus at 15, and her story catapulted her to international fame.
Following her shooting she was transported to the UK for treatment in Birmingham, where her family continue to live.
Since winning the Nobel Peace Prize in 2014, she has continued campaigning while pursuing studies at Oxford University.
She has repeatedly expressed her wishes to return to Pakistan, including at the World Economic Forum in January this year.