Group bookings at New South Wales pubs will be capped at 10 people, down from 20, in new Coronavirus measures due to be announced tomorrow.

The same guidelines will see bigger venues have their capacity capped at 300.

The new restrictions will only be applicable to pubs and not clubs, restaurants or Star Casino.

The changes come as 21 cases of COVID-19 have been linked to the Crossroads Hotel in Casula.