Brazil has surpassed six million confirmed cases of Covid-19, the health ministry said, as the world's third-worst coronavirus outbreak begins to surge again amid fears that a second wave is underway.

The South American nation joined the United States and India as the only countries to have passed the six million mark. With almost 170,000 confirmed fatalities, Brazil has the world's second highest death toll.

After three months of falling numbers since peaking in late July, infections are increasing again, government data shows, according to Reuters.