The policemen are driving the demonstrators away.
Keikan ga demotai o oimakutteiru.
indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and
indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.
to disperse; to chase away; to pursue relentlessly; to be in hot pursuit