Three people have died in the Northern Territory (NT) in a horror start to the region's 2019 flu season, Trend reported citing Xinhua.

A spokesperson for NT Health told News Corp Australia on Tuesday night that three people have already been killed by the flu season but did not say where the deaths took place.

It comes before the flu season has properly begun, with most cases usually occurring in the winter months between June and September. There were only six deaths in the entire flu season in the NT in 2017.

The spokesperson urged eligible Territorians to make the most of free flu vaccines offered to children aged between six months and five years, those aged 65 years and over, pregnant women and all indigenous Australians aged six months and older.

"If more people are vaccinated, less disease will circulate and the number of hospitalisations and deaths from influenza infection will decrease," she said.

As of the first week of April nearly 27,000 Australians had been diagnosed with the infection, almost half the total number of cases diagnosed in 2018.