China on Saturday marked the 33rd anniversary of the crackdown on the Tiananmen Square democracy protests with tight security, months before the ruling Communist Party's twice-a-decade congress in the fall.

Uniformed police officers were keeping a close watch in and around the square with the aim of containing any potential commemorative demonstrations, at a time when many people in Beijing have become fed up with strict regulations under the country's radical "zero-COVID" policy.

Police officers are pictured in front of Beijing's Tiananmen Square on June 4, 2022, the 33rd anniversary of the bloody military crackdown on the pro-democracy protests in and around the square. (Kyodo)

Last year, the ruling party adopted a pivotal resolution on the nation's modern history that identified the quashed pro-democracy protests in the square in 1989 as a "political disturbance."

Chinese President Xi Jinping has been pursuing political stability recently as he strives to secure a controversial third term as leader at the upcoming congress, foreign affairs experts said.

Following the 1989 death of Hu Yaobang, sacked as general secretary of the Communist Party two years earlier for his liberal leanings, students rallied to call for democracy and government action against rampant corruption. Support for the protests grew as people poured into Tiananmen Square.

Chinese authorities tighten security at a burial site for those killed in the 1989 Tiananmen Square crackdown on pro-democracy protests in Beijing on June 4, 2022, the 33rd anniversary of the incident. (Kyodo) ==Kyodo

The protests defied martial law, declared in late May that year, and inspired big rallies across China.

But from the night of June 3 through the early hours of June 4, troops and armored vehicles cleared the square by force, killing hundreds of protesters and bystanders.

Intent on maintaining its firm one-party rule, the Communist Party has justified the 1989 killings by declaring it was necessary to quell political unrest. Open discussion about the incident remains taboo in China.