OAKLAND, Calif. » Authorities say a 66-year-old Buddhist monk was critically injured when a fellow monk stabbed him in a San Francisco Bay Area home.

Oakland police say they are searching for a suspect and that no arrests have been made since the attack Tuesday. The victim is a monk at the Branch of International Community of Khmer Buddhist Monks Center, near where the assault happened.

San Hin, who said he drove the injured monk to the hospital, said he is unsure what sparked the dispute. He said the suspect, who he and the police declined to identify, recently joined the monastery.

Police say they are unsure of the motive as well.