A local court on Friday sentenced an activist to three years in prison for organizing violent rallies in central Seoul over a deadly ferry disaster.

Still, the Seoul Central District Court suspended the sentence for Park Rae-gun for four years and ordered him to perform 160 hours of community service.

The 55-year-old activist was convicted of holding unauthorized rallies and injuring police officers in 2014 and 2015 over the ferry sinking.

The 6,825-ton ferry Sewol sank in waters off the country's southwestern coast in 2014, killing a total of 304 people, mostly high school students on a school trip.

Thousands of demonstrators staged rallies at Seoul Plaza in front of Seoul City Hall in April and May 2015 to mark the first anniversary of the sinking of the ferry.

Police clashed with demonstrators as they tried to march to Cheong Wa Dae, South Korea's presidential office.

"Despite the fact that he had been punished for committing similar crimes in the past, he obstructed traffic by holding rallies without reporting to the authorities and injured police officers in cahoots with protesters," the court said. (Yonhap)