Japan's sumo world has once again been rocked by violence with the sport's governing body announcing Wednesday that rank-and-file wrestler Takanoiwa assaulted a stablemate during the ongoing regional tour.

According to the Japan Sumo Association's public relations department head, Takanoiwa, who was a victim of assault last year, struck a lower-ranked attendant of his Chiganoura stable four to five times with an open hand and his fist at a hotel because the junior wrestler had forgotten to bring something.

The apprentice did not suffer a major injury but has swelling on his face, according to the association.

Takanoiwa has withdrawn from the winter regional tour in Fukuoka and has already been questioned by the director of JSA's crisis management department and apologized for the incident. The association plans to hear Thursday from the apprentice and will then decide on a punishment for the Mongolian wrestler.

(Harumafuji)

The incident occurred just two months after the JSA issued a "declaration to eradicate violence," following a spate of scandals that have occurred since Takanoiwa himself was assaulted by former grand champion Harumafuji last year.

Takanoiwa, whose real name is Adiyagiin Baasandorj, was beaten with a karaoke machine remote control at a lounge bar by fellow Mongolian Harumafuji on Oct. 26 last year, resulting in Harumafuji's retirement the following month.

The 28-year-old from Ulan Bator was hospitalized with head injuries that required 12 days to heal and forced to sit out two grand tournaments before returning to competition in March.

Last month, Takanoiwa dropped a damages suit filed against Harumafuji, saying his family in Mongolia had been subjected to abuse over the legal action by compatriots who hold Harumafuji in high regard.

The scandal prompted former yokozuna Takanohana, the head of Takanoiwa's stable until it was dissolved, to quit the Japan Sumo Association in September.

Sumo has struggled to rebuild its tarnished image over the last decade, after being shaken by a string of scandals that have severely damaged its reputation.

(Takanoiwa and Takanohaha)