Apple is being slammed by US Congress members for censoring content on Apple Music to appease China ahead of the 30th anniversary of the "Tiananmen Square Massacre".

Under pressure from China, Apple Music has removed songs with lyrics that refer to the massacre -- one of the biggest of all times, The Verge reported on Saturday.

"It's disgraceful to see one of America's most innovative, influential tech companies support the Communist government's aggressive censorship efforts within China as we near the Tiananmen Square massacre's 30th anniversary," the report quoted Marco Rubio, the US Senator for Florida as saying.

Several other Congress members felt by surrendering to China's repressive mentality, the iPhone-maker was missing the chance to "become a stronger voice for freedom around the globe."

Thousands of pro-democracy protesters were killed and thousands arrested when Chinese troops stormed the Tiananmen Square in Beijing firing on June 4, 1989.

Every year, around June 4, the Chinese government begins to censor mentions of the protest and this time Apple joined in, especially on its music platform, the report said.

One of the songs removed is "The Path of Man", written by James Wong. Wong confirmed that lyrics referred to the Tiananmen Square protests and showed the Chinese government in poor light. Two other singers censored by the app are pro-democracy activists Denise Ho and Anthony Wong.

As Apple expands its retail operations in China, it has grown increasingly aligned with the country's government. Last year, it moved the data of its Chinese users to a local firm in southern China to gain government trust.

In accordance with the Chinese line that Taiwan is its part, the company has censored the Taiwanese flag emoji in China. It even created a bug that crashed users' phones when they received texts containing the Taiwanese flag emoji.