Hertha made the gesture before the Oct. 14 Bundesliga match at home against Schlake to support the protests initiated by then San Francisco 49ers quarterback Colin Kaepernick and "to take a stand against discrimination."

It had been the first time a European team picked up on the protests, with the players and staff taking a knee in the Olympiastadion, built for the 1936 Olympic Games under the German Nazi regime.

Speaking to ESPN FC, Ivory Coast international Salomon Kalou explained the action, and said that they were "to protest against people who think that there is a colour, there is a kind of white supremacy."

In 2016, Colin Kaepernick kneeled during the U.S. anthem before games to protest police brutality and racial oppression. While the act was taken up by other prominent athletes, a backlash against the movement has since emerged that includes last month's criticism from U.S. President Donald Trump.

"Taking a knee has nothing to do with the flag, but rather showing that we are one as people and that we going to rise together," Kalou said. "A human heart is too tiny to have a place for hate, because hate is such a horrible thing to put in your heart. I feel bad for people who have a lot of hate in their heart."

While the protests made international headlines, parts of the German media were highly critical of the Bundesliga side taking a knee. Spiegel Online said it was "irrelevant" while broadsheet Suddeutsche Zeitung called it "an artificial construct for the purposes of ingratiation and gaining an air of importance."

But Kalou rejected those claims, telling ESPN FC: "Some people will see it the wrong way, see it as a PR campaign. I think that if you are against [racism] then you should do something about it. Or if you're not [doing something about it], you should not be criticising people who do something about it.

"Those people who say that you should do something about it: They can't deny that this kind of behaviour exists. If you say that about people who do this then you should do something to show that you are against that way of behaviour. For me racism is like terrorism."

Having played for four European clubs since 2004 and in the Dutch Eredivisie, the Premier League, France's Ligue 1 and now the Bundesliga, the former Chelsea forward said he never experienced racism in football himself.

But he added: "I have people who I know who have been through this kind of situation, and that's sad.

"It's sad that people in 2017 are still thinking that kind of way because I think we are way past the time that this was okay."

The 32-year-old also elaborated on incidents at the recent Champions League match between Chelsea and Roma when some of the away supporters allegedly directed monkey chants at Blues and former Roma defender Antonio Rudiger.

The Italian club have since been charged with racist behaviour by UEFA, and Kalou said: "I don't think that's acceptable that this kind of people try to come to football and show their way of thinking."