Tanzanian vice-president Samia Suluhu Hassan was sworn in as president, two days after the death of incumbent John Magufuli, and now faces the arduous task of securing political control of the East African nation.

Hassan, 61, took the oath of office at a ceremony in the commercial hub of Dar es Salaam on Friday. She succeeded Magufuli under a constitutional provision that the president’s deputy will serve out their term if they die in office...