A court in southern Vietnam has sentenced a medical doctor to 4 years in prison for writing and posting dozens of articles on social media that the court says tarnished the image of the country's leaders and instigated people to demonstrate and boycott local elections.

The state-run Thanh Nien newspaper reported Ho Van Hai, 54, was convicted of spreading propaganda against the state Thursday at his one-day trial in Ho Chi Minh City.

Hai had blogged under the name BS Ho Hai or Doctor Ho Hai and was arrested in November 2016.

The Communist Party state has stepped up a crackdown on dissent.

Seven people have been convicted and given jail sentences for spreading propaganda against the state over the past two weeks.