Beijing’s foreign affairs office in Hong Kong has hit back at what it called “irresponsible” remarks by the European Union after it voiced support for three activists who were jailed for refusing to help a police investigation into the group behind the city’s Tiananmen Square vigil.

The Commissioner’s Office of China’s Foreign Ministry in Hong Kong on Sunday accused the EU of interfering in the internal affairs of the nation and the city, “vilifying” the judicial process and trampling on the principles of international law and the norms governing international relations.

Defending Saturday’s sentencing of the trio, a spokesman said: “The judicial ruling reflects the principle that laws must be enforced, and that lawbreakers must be held accountable. It is a necessary action to safeguard the authority of the national security law and it brooks no slander.”

In a separate statement, the Hong Kong government said it “strongly disapproved and firmly rejected” the scandalising of the criminal judicial process by the EU official, stressing cases would never be handled differently due to the profession, political beliefs or background of the persons involved.

The comments came hours after the EU voiced its support for Chow Hang-tung, Tang Ngok-kwan and Tsui Hon-kwong, who were each sentenced to 4½ months in jail for refusing to help police in an investigation into alleged breaches of the national security law by their group, the now-defunct Hong Kong Alliance in Support of Patriotic Democratic Movements of China.

Nabila Massrali, the EU’s spokeswoman for foreign affairs.

Nabila Massrali, the EU’s spokeswoman for foreign affairs and security policy, tweeted on Saturday that the sentencing was “another example of the authorities abusing legislation to suppress fundamental freedoms”.

Chow, Tang and Tsui were three core members of the alliance, which had organised the city’s Tiananmen Square candlelight vigil on June 4 each year.

The trio were jailed for rejecting a police request for details about the alliance’s members, donors, financial reports and activities. They were convicted earlier this month under implementation rules of the Beijing-imposed national security law.

Chow was formerly vice-chairwoman of the alliance, while Tsui and Tang previously worked as standing committee members.

Two other ex-standing committee members, Simon Leung Kam-wai and Chan To-wai, earlier pleaded guilty and served a three-month sentence.

The commissioner’s office also hit out at Western politicians whom it said had tried to “whitewash” anti-China forces in the city whenever there was any law enforcement actions involving them.

Tsui Hon-kwong (left) and Tang Ngok-kwan.

“[It] only shows their collusion with anti-China elements in Hong Kong and exposes their fear of the national security law,” the spokesman said, while stressing that Beijing was unwavering in its determination to safeguard national sovereignty.

Last month, the EU reiterated its concerns to Beijing during a human rights dialogue over civil liberties in Hong Kong, including free speech and freedom of peaceful assembly and association.

During the meeting, the EU addressed crackdowns on human rights defenders, lawyers and journalists in mainland China and Hong Kong.