A seven-year-old boy was stabbed to death walking home from school in Switzerland Thursday, police said, adding that a 75-year-old woman had turned herself in.

Read all the latest news on this story here.

The child was attacked while he was walking alone home from school in the northern Swiss city of Basel at around 12:30 pm, local police said in a statement.

The boy's teacher found him lying on the ground in a serious condition and called for an ambulance. Despite efforts to resuscitate him, he was declared dead at the hospital, police said.

Shortly after the stabbing, a 75-year-old woman turned herself into authorities, admitting to having attacked the child, and was arrested.

Police said they were still investigating the motive of the crime.

Speaking to Swiss media, the spokesperson for the state prosecutors office in the canton of Basel, Peter Gill, described Thursday's attack as a “very serious” and “terrible” crime.

He said investigators had “absolutely no idea” what the motive for the attack might have been.

Meanwhile, a spokesperson for the Basel-Stadt education department said school psychologists would be on hand on Friday morning to talk to classmates and schoolmates of the murdered boy.