TOKYO, July 1 (Xinhua) -- A man was left in critical condition after being stabbed at a law office inside a high-rise building in Tokyo's Ikebukuro district on Tuesday, local media reported.

According to the Tokyo Metropolitan Police Department, the incident occurred around 11:50 a.m. local time at a law office in Higashi-Ikebukuro, Toshima Ward.

A man in his 50s allegedly wielded a knife and attacked a male employee, who was transported to the hospital unconscious and in critical condition, national broadcaster NHK reported.

Following the incident, the suspect turned himself in at a nearby police station.

Authorities are investigating the cause of the stabbing. ■