Three backers of the Maccabi Tel Aviv soccer team were arrested in early morning raids on Tuesday for verbally assaulting the team’s midfielder, Arab-Israeli player Mahrhan Radi.

The arrests came after a police undercover investigation over the past few weeks.

“We are acting, and will continue to determinedly act, with zero tolerance against any signs of violence in sport, wherever it happens,” Tel Aviv District Commander Major General Benzi Sau said. “We will apply every effort and force to enable the pubic that comes to the field to enjoy sporting events. My message to that handful of fans that arrive to curse and disrupt is — not in our school.”

The supporters are suspected of having been among those who burst onto the pitch during a training session of the Maccabi Tel Aviv team two weeks ago and shouted racist remarks at Radi.

In addition, police said, the fans were documented on several occasions making racists calls during practice and official games in the past few weeks.