A 14-year-old student was killed after being assaulted with a metal bar during a fight, believed to be with a senior citizen, in Bestari Jaya, Kuala Selangor on Sunday.

Selangor CID chief Datuk Mohd Adnan Abdullah said the victim suffered serious bleeding on his right thigh in the incident.

He said the police received a call from the Sungai Buluh Hospital at 10.40pm to inform that the victim had died when taken to the hospital.

"In a follow-up to the incident, we detained a local senior citizen, aged 70, early Monday morning, believed to be involved in the killing," he told reporters after a function at the Selangor Police Contingent Headquarters here, last night.

Mohd Adnan said the police also seized a metal bar and a blood-smeared shirt believed to belong to the suspect.

He said the man was remanded until tomorrow to help in investigation under Section 302 of the Penal Code.