In a simple act of solidarity, Dutch men across the Netherlands and around the world have held hands this week to protest the beating of two gay men. The attack has shaken a nation that has long prided itself on its tolerance.

The beating happened early Sunday morning in the eastern city of Arnhem — long seen as one of the world’s most welcoming places for same-sex couples. The city’s mayor conducted the world’s first gay marriages in 2001.

Arnhem police said on Facebook that the couple stated they were verbally abused by a group of young people armed with bolt cutters because they were walking hand-in-hand over a bridge. In the confrontation that followed, both men were injured, and one had his front teeth smashed out.

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The couple, Jasper Vernes-Sewratan and Ronnie Sewratan-Vernes, posted their own account of the attack on social media.

Helaas zijn Ronnie en ik dan ook slachtoffer geworden van een hate-crime richting homo's 😞, na het stappen in Anhem zijn... Posted by Jasper Vernes-Sewratan on Saturday, April 1, 2017

In response to the incident, a Dutch journalist called for support for the couple on Twitter, writing: “Can all men (straight and gay) please just walk hand in hand this week.” Her idea spaked the viral hashtag #allemannenhandinhand, or “all men hand in hand.”

Kunnen deze hele week alle mannen (hetero en homo) alsjeblieft gewoon hand in hand lopen... — Barbara Barend (@barbarabarend) April 2, 2017

The idea took off, and men in the Netherlands and beyond began posting photos of themselves holding hands. Hundreds of people walked hand in hand through the streets of Amsterdam. The Dutch deputy prime minister, finance minister, sports stars, and TV personalities all joined in to express solidarity. Dutch Prime Minister Mark Rutte weighed in, too, calling the Arnhem incident “terrible.”

Male colleagues of @NLatUN walking hand in hand in New York protesting against violence directed at LGBTI #allemannenhandinhand pic.twitter.com/AYThVsymep — Lise Gregoire (@LiseGvH) April 3, 2017

Male colleagues from the Dutch Embassy London holding hands in protest against violence towards the LGBTQIA community. #allemannenhandinhand pic.twitter.com/Bp6Mz6UiyY — Dutch Embassy London (@NLinUK) April 4, 2017

The incident has touched a raw nerve in the nation, where tolerance on other fronts has eroded in recent years with the rise of anti-Islam and anti-immigrant populism and a tightening of the country’s famously liberal drug policies.

“I find it really absurd, unbelievable, and this is feeling like we are going backwards,” said Sjag Kozak, an Israeli who married his husband in Amsterdam and has lived in the freewheeling Dutch capital for 21 years.

“In the Netherlands we think that it’s normal to be able to show who you are as a person, but apparently for some people it’s not,” said lawmaker Alexander Pechtold.

Five suspects, all in their teens, were to be charged Thursday with causing serious bodily harm, prosecutors said, adding that they are still investigating the motive of the attack.