By Victoria Cavaliere

SEATTLE (Reuters) - An 18-year-old Washington state high school student died after agreeing to take a single punch to the face from a classmate to settle a dispute outside a weekend house party, local officials said on Tuesday.

The victim, identified as Jarom Thomas of Lake Stevens, about 35 miles north of Seattle, died on Sunday of blunt force injuries to the head, the Snohomish County Medical Examiner's Office said on Tuesday. The manner of death was homicide, the medical examiner said.

An 18-year-old classmate, Michael Shane Galen, was arrested late Sunday on a second degree manslaughter charge for punching Thomas in an apparent altercation over a minor fender bender, according to the Snohomish County Sheriff's Department and court filings.

According to the court documents, Thomas earlier on Sunday had backed his car into a parked vehicle where Galen was sitting, then drove away. He returned a short time later and the two young men got into an argument, the documents said.

They agreed to "resolve" the issue by allowing Galen to punch Thomas once in the face and shook hands before the fatal strike, according to the documents.

"Witnesses said the suspect punched the victim in the face and the victim fell backwards, unconscious," the Snohomish County Sheriff's Department said in a statement.

A friend drove Thomas to the hospital, where he died from his injuries, the statement said.

Galen was released from Snohomish County jail on Monday evening after posting $10,000 bond, online records show. It was unclear if he had obtained an attorney.

Galen's father, Michael Galen Sr., told the Herald newspaper in Everett that agreeing to take a punch is apparently part of a code among young people to settle differences.

"I'm so sorry for the family for what has happened," he told the newspaper.

Both teens were students at Crossroads High School in Granite Falls, Washington, police said.

(Editing by Alex Dobuzinskis and Susan Heavey)