Mozambican President, Filipe Nyusi, has denounced the sale of cards proving a Covid-19 vaccination.
He said the move was "jeopardising the health and lives of all people".
President Nyusi urged the public to be vigilant.
“We want to draw attention, once again, to regret the situation of buying and selling vaccination cards. This type of conduct has no other name than this: It is a crime. More than a forgery," he said in a national address.
Mozambique has vaccinated more than 650,000 people with more than 1.9 million doses administered.
The health ministry has been running public campaigns encouraging people to turn up for mass vaccination as coronavirus cases in the country increase.