South Korean online portals Naver and Daum have removed the viewer comment section on sports news stories.

In a notice posted on its blog Friday, Naver said it is temporarily suspending the service that allows readers to post their opinions.

The firm said derogatory, slanderous comments targeting certain athletes have continued despite stronger monitoring, and it believes the attacks and pain inflicted on athletes have reached a point that can no longer be tolerated.

Stressing that the removal of the comment section is not permanent, Naver said it is in the process of developing technology that can automatically regulate the exposure of vicious comments.

Kakao Corporation, the operator of Daum, also announced similar measures Friday, citing ongoing comments that defame certain athletes, teams and regions.

Naver and Daum previously suspended viewer comments for entertainment news articles back in February and last October respectively.