Three people were killed and one injured in a sword attack at a prominent shrine in Tokyo on Thursday evening, Japanese news agency Jiji Press reported.

The head priest of the Tomioka Hachimangu shrine, 58-year-old Nagako Tomioka, was killed allegedly by her brother, Shigenaga. A woman in her 30s – suspected to be an accomplice – also died, the Metropolitan Police Department said.

Shigenaga allegedly attacked his sister as she got out of her car, AP reported. His accomplice, meanwhile, targeted the driver with a samurai sword and pursued him as he ran out of the temple grounds. After killing his sister, Shigenaga killed the female suspect and then committed suicide, Jiji reported.

The priest’s driver was injured.

The motive behind the murder was unclear, but Japanese media reported it may have been because of a longstanding feud between the priest and her brother over succession.