The outpouring of support came after the married couple, Jasper Vernes-Sewratan and Ronnie Sewratan-Vernes, said they were attacked by a gang of youths while holding hands on their way home from a party early Sunday.
According to a statement the Arnhem police posted on Facebook, the two said they had been attacked by men wielding bolt cutters; one had some of his teeth smashed out.
Prosecutors said five teenage suspects would be charged on Thursday with serious bodily harm. The authorities are still investigating the motivation for the attack, which the victims have characterized as a hate crime.
The beating caused particular outrage in the Netherlands, which has long prided itself on its tolerance. Amsterdam, the capital, has been a haven for sexual minorities for centuries, and it has marketed itself as the “gay capital of Europe.” Homosexuality was removed from the Dutch criminal code in 1811, and the Netherlands was the first country in the world to legalize gay marriage, with the first ceremonies in 2001.
Gay rights are supported across the political spectrum in the Netherlands. The attack comes as the country has been grappling with growing anti-immigrant sentiment, fueled in part by the far-right leader Geert Wilders, who has railed against immigrants and Muslims in particular, saying that “Islamization” is a threat to European liberal values, including homosexual and women’s rights.
The populist party of Mr. Wilders, who likens himself to Donald Trump, came second in recent Dutch elections. He is an ideological heir of Pim Fortuyn, a right-wing politician who derided Islam, immigration and multiculturalism, and who was openly gay. Mr. Fortuyn was killed in 2002, days before his party placed second in national elections.
The Dutch news media quoted Gerald Roethof, a lawyer for one of the suspects, as saying that the couple had instigated the fight by acting aggressively toward the teenagers, an accusation the two vehemently denied. Mr. Roethof also denied that bolt cutters had been used, or that the men were targeted because they were gay. But he said his client had acknowledged punching one of the men in the mouth.
Mr. Sewratan-Vernes, 31, one of the victims, told the Dutch public broadcaster NOS that he and his husband seldom held hands in public for fear of provoking an attack. “But we’d had a nice evening, it was late, and we thought we were alone,” he said.
Then suddenly six to eight youths set upon them, he said, and “before I knew it, I was on the ground fighting with three men on top of me.”
After the attack, which Mr. Vernes-Sewratan, 35, recounted on his Facebook page, Dutch politicians, actors, police officers, soldiers and athletes took to the streets, holding hands. Hundreds of people marched through the streets of Amsterdam to show their support for gay rights. The expressions of support grew after the journalist Barbara Berend appealed on Twitter for men, whether straight or gay, to walk hand in hand.
Dozens heeded her call and posted photographs of themselves doing just that, often with the hashtag #allemannenhandinhand (all men holding hands). Two high-profile politicians — Alexander Pechtold, leader of the liberal-democratic party D66, and Wouter Koolmees, a lawmaker in the party — showed up for coalition talks on Monday holding hands.
COC Netherlands, an advocacy group for gay rights based in Amsterdam, said the number of reported cases of violence against gay men, lesbians, bisexuals and transgender people had increased to 1,600 in 2015 from about 400 in 2009. Of the 1,600, nine were convicted of discrimination-related offenses, including hate crimes.
It cautioned, however, that the increase in reporting could also be due to greater awareness of the issue.