File photo: Samia Hassan Suluhu (L) and Tanzania's late President John Magufuli (C) speak with Kenya's President Uhuru Kenyatta on the phone at the State House in Dar es Salaam, Tanzania, on July 24, 2019. /AFP

Samia Suluhu Hassan on Friday was sworn in as Tanzania's first female president after the sudden death of John Magufuli from an illness shrouded in mystery.

"I, Samia Suluhu Hassan, promise to be honest and obey and protect the constitution of Tanzania," said the 61-year-old dressed in black suit and red headscarf before dignitaries at a ceremony in Dar es Salaam.