During the early morning hours of 13 June, the man, known only as Bart, was on his way home from an evening out when he was jeered at and jostled near the Stock Exchange on Anspachlaan. He fled in the direction of a group of people standing outside a nearby pita restaurant, where he was tripped, attacked with chairs and choked. The staff of the restaurant called the police. One of the attackers was arrested and said later by police to be of Guatemalan origin. Two others, identified by CCTV camera images, are being sought.

The incident immediately provoked a strong reaction from gay politicians and community leaders. Pascal Smet, Flemish minister for equal opportunities and youth, accused bands of youth of acting like “the morals police” – a reference to the mutaween in Saudi Arabia, whose job it is to publicly enforce a strict interpretation of Islam.

According to Bruno de Lille, Brussels’ secretary of state for equal opportunities, violence against gays is not on the increase in Brussels. De Lille had previously written in an opinion piece in De Standaard of his reluctance to embrace or even hold hands with his partner in public because of possible reactions. A campaign that his department has been running since April aims to encourage the victims of homophobic violence to make an official complaint.

Last year the Centre for Equal Opportunities received 215 complaints of harassment from gay people, a figure described by director Jozef De Witte as “not very high”. But many victims find it too difficult to take the step of making a complaint, he dais, and the number of official complaints was likely “just the tip of the iceberg”.

De Lille also disputed the common view that those responsible for most of the violence and intimidation are Muslim youths. “There is no link to religion, more to a macho culture,” he said. “We see that, too, with Eastern European suspects. People who make insulting remarks to women often do the same thing to homosexuals.”

De Clerck’s call for tougher treatment of those who resort to homophobic violence and intimidation was echoed by Annemie Turtelboom, the federal interior minister whose responsibilities include the police. Turtelboom said she was “shocked” by reports of the attack, “especially in a country where gay people have so many rights. Homophobic violence absolutely cannot be tolerated”.

Last weekend on the Grote Markt in Antwerp, some 6,000 people blew whistles for a full minute in a symbolic rejection of homophobia. “The noise was deafening,” said one of the organisers, radio presenter Sven Pichal. “We’ve heard many stories in recent days from people who were confronted with homophobia but never made a complaint. Since there are so few people who go public, it makes us think the problem is being underestimated.”

The “whistle concert” – a pun on the Dutch word for “to make catcalls” – coincided with the week-long Antwerp Pride event, which attracted an estimated 60,000 people.

In Brussels, meanwhile, some 300 couples took place in a kiss-in on the Grote Markt to protest at intimidation of gay people on the streets of the city. “We’re sick of all these hate crimes,” said organiser Neil Verduyckt. “We’re here, and we have the right to love who we want to – and to let it show.”