In a move unprecedented for Tanzania, Vice-President Emmanuel Nchimbi has announced he is resigning and will retire from public life at the end of next week less than 10 months after being sworn in.

The 54-year-old gave the details in a brief letter to President Samia Suluhu Hassan shared on his Instagram account. Sources in his office and the presidency confirmed the resignation.

Nchimbi, who will be the first vice-president to step down since independence in 1964, explained he was quitting in line with a promise he made to the president that he would go if she felt another vice-president was needed.

The resignation comes amid media reports that Samia had fallen out with her deputy.

Nchimbi was sworn in last November after a successful campaign as Samia’s running mate in the presidential election the previous month. The outcome, with the winner taking a 98% share of the vote, was disputed by the opposition and violent protests led to the deaths of at least 500 people according to an official enquiry.

Opposition parties and human rights groups accused the security forces of unleashing a brutal crackdown on anti-government protesters.

“I have become convinced, without doubt, that the president wants changes, and I have therefore decided to fulfil my promise,” Nchimbi wrote in his resignation letter referring to the pledge he had made to Samia.

He thanked the president and the ruling Chama Cha Mapinduzi (CCM) party for the trust they had placed in him, and to Tanzanians for their support during his time in public service.

He said he was leaving office in accordance with the country’s constitution and would continue to be a “good citizen of Tanzania”.

Nchimbi previously served as secretary-general of CCM. He also held several senior positions in government, including both minister of information and home affairs, before becoming Tanzania’s ambassador to Brazil and later Egypt.