Irish police have launched an investigation into former two-division UFC champion Conor McGregor after he expressed outrage over the vicious Nov. 23 stabbing of three young children and their caregiver outside a primary school in Dublin.

According to the Sunday Times, assistant Garda Commissioner Justin Kelly is leading an Irish police investigation into whether McGregor has disseminated online hate speech.

Two little girls, ages 5 and 6, a 5-year-old boy, and the children’s caregiver, a woman in her 30s, were stabbed by a suspect allegedly of Algerian origin outside Dublin primary school Gaelscoil Cholaiste Mhuire around 1:30 p.m. on Thursday.

Eyewitness Siobhán Kearney told the Irish Times she had heard “screaming” and “spotted a guy with a stabbing motion across the road.”

“So I took across the road and there was fellas there and they pulled the guy off the children. There was a good few kids,” said Kearney.