Burundi's President Pierre Nkurunziza has said he will not seek another term in office after the end of his current mandate in 2020.

He made the announcement in Bugendana, in Gitega province, where the country's new constitution was signed into law, reports BBC's Cyriaque Muhawenayo from the ceremony.

Last month, Burundians voted overwhelmingly in a referendum to back constitutional reforms, which include extending presidential terms from five to seven years.

Many had believed Mr Nkurunziza actively sought the change to term limits so that he could stay in office until 2034.

The 54-year-old leader ran for a controversial third term in 2015, a move which set off a wave of violence and an attempted coup that was foiled by government forces.The political crisis led to hundreds of deaths and more than 400,000 people fled the country.