US Marshals have offered a reward for information that leads to the arrest of two parents charged with involuntary manslaughter over a Michigan high school shooting.

But the pair’s lawyer has said they had left town for their own safety and were returning to face arraignment.

Shannon Smith spoke after authorities said they were searching for Jennifer and James Crumbley. They are the parents of Ethan Crumbley, who is charged with murder and terrorism following the deaths of four students at Oxford High School on Tuesday.

Crumbley’s parents were charged on Friday. A prosecutor says they gave their son access to a gun and did not intervene despite problems at school that day.US Marshals on Friday night announced a reward of up to 10,000 dollars (£7,557) each for information leading to the Crumbleys’ arrest.

In a text message, Ms Smith says the parents have not fled from authorities. She did not say when they would appear in court.

Seven students and a teacher were shot before Crumbley surrendered to sheriff’s officers.

Three of the students died on Tuesday and the fourth died on Wednesday in hospital.

The semi-automatic gun used in the shooting was purchased legally by Crumbley’s father last week, according to investigators.