A woman from Tennessee, US, is believed to have killed her four adopted Chinese children before turning the gun on herself, local Sheriff Bucky Rowland confirmed in a news conference on Tuesday.

The motive is still under investigation, but the mom was believed to be suffering from mental illness, the Nashville Tennessean reported, quoting the sheriff.

“She appeared to be ’a very loving mother’ except for this incident, and she appears to have suffered from mental health issues”, Rowland said.

The teenaged victims, including one 17-year-old boy and three girls aged about 14, had been adopted and home-schooled in what appeared to be a loving home, as there were no previous reports of violence at the home. The report said a sibling found the bodies and called police.