Zanzibar’s First Vice-President, Seif Sharif Hamad, has tested positive for Covid-19 together with his wife.
Some of his aides have also contracted the virus, his party ACT Wazalendo said in a statement.
Mr Hamad was hospitalised and his condition has been said to be improving.
The opposition party urged Tanzanians to follow public health guidelines to prevent the spread of coronavirus.
The news comes days after Tanzania’s President John Magufuli warned health officials against acquiring Covid-19 vaccines, saying – without giving evidence – that they could harm the population.
The country stopped publishing official data about coronavirus in June last year and President Magufuli declared it coronavirus free.
