The Oakland Police Department says they are assisting BART police with the ongoing criminal investigation.
The two men were taken to a local hospital for treatment.
In Facebook video posted by a witness, one of the men appears to be unresponsive while police and paramedics give him aid. A woman is heard asking if he is dead.
Seventh Street between Mandela Parkway and Center Street has been cordoned off in both directions as well as associated side connecting streets
AC Transit says they are not servicing the station at this time.
BART is operating as normal.