BEIJING -- China has strengthened its public interest litigation to protect the lawful rights and interests of minors, the Supreme People's Procuratorate (SPP) said on Monday.

Prosecutors across the country opened 6,633 public interest cases concerning the protection of underage people in 2021, SPP prosecutor Na Yanfang said at a press conference.

That is 4.2 times the figure seen in 2020, or 3.3 times the total seen between 2018 and 2019, according to the prosecutor.

While less than 30 percent of the cases are traditional, mainly concerning food and drug security, more than 70 percent are new types of cases involving tobacco or liquor sales, online gaming, facility security, on-demand cinemas and esports hotels, the SPP said.

Five typical cases were released at the press conference for prosecution reference.

The top procuratorate vowed to further improve its work and scale up prosecution in the future. Normative documents and guidelines will be rolled out to make the work more targeted, standardized and effective, the SPP said.