A woman in her 30s lost consciousness and died after being subdued by police officers in Obihiro, Hokkaido, on Aug 2, police said.

According to Hokkaido Prefectural Police, a local resident called 110 around 3:25 a.m. on Saturday, saying that a woman was screaming outside, Sankei Shimbun reported.

When two officers arrived, the woman was partially undressed and pacing up and down the street, yelling. The officers attempted to speak to her, but she responded incomprehensibly.

The officers restrained her face down on the ground, holding her hands and back. The woman lost consciousness shortly afterward, and was taken to hospital where she died at around 9:40 a.m.

Police said an autopsy revealed acute cardiac failure as the cause of death. They stated that there was no causal relationship between the woman's death and the police officers' response. No traces of drugs or alcohol were found in the woman's blood.