KINGSTON, Ont -- A Montreal man charged with killing four members of his family has reportedly been assaulted at a detention centre in Napanee, Ontario.

The Kingston Whig-Standard says 18-year-old Hamed Shafia was attacked by other inmates at the Quinte Detention Centre.

The paper says it happened when jail staff allowed Shafia to exercise with other protective custody prisoners who were thought to be compatible.

The report says Shafia was not seriously injured.

Shafia, his father, and mother were charged last Thursday with four counts of first-degree murder and four counts of conspiracy to commit murder.

A car containing the bodies of Hamed Shafia's three sisters and his father's first wife was pulled from the Rideau Canal near Kingston four weeks ago.