LOS ANGELES (AFP) — The Women’s National Basketball Association (WNBA) said it had launched an investigation into allegations of "hateful" fan comments during the Indiana Fever's season-opening clash with the Chicago Sky.

Indiana's 93-58 win over Chicago on Saturday made headlines after a flashpoint in the third quarter when Sky star Angel Reese was fouled by Indiana's Caitlin Clark.

Reese, who has a long-time rivalry with Indiana prodigy Clark since their collegiate careers, reacted angrily after being bundled over by the Fever ace as she drove to the basket.

A furious Reese needed to be restrained by teammates after moving to confront Clark following the incident. Clark turned and walked to the other end of the court as Reese gesticulated.

The Indianapolis Star reported on Sunday that the WNBA's investigation was looking into allegations of racist abuse against Reese by sections of Indiana's home crowd.

"The WNBA strongly condemns racism, hate, and discrimination in all forms — they have no place in our league or in society," the WNBA statement said.

"We are aware of the allegations and are looking into the matter."

Indiana said the team was assisting the WNBA in its investigation.

"We are working closely with the WNBA to complete their investigation," the team said.

"We stand firm in our commitment to providing a safe environment for all WNBA players."

The latest allegations echoed incidents last season when Indiana fans were accused of racially abusing some of Clark's WNBA rivals.

Clark spoke out against the issue at the end of the season, describing fans who racially abused WNBA players as "trolls."

"Nobody in our league should be facing any sort of racism, hurtful, disrespectful, hateful comments and threats," Clark said.

"Those aren't fans, those are trolls, and it's a real disservice to the people in our league, the organization the WNBA."