Breaking News: Sydney is on high alert today, as the latest covid outbreak spreads.

Sydney Christmas time suddenly becomes very complicated as cases are tracked across the city.

NSW Chief Health Officer Kerry Chant said this Sydney Christmas outbreak in coronavirus cases linked to the northern beaches cluster, including one which was tested in Queensland, the SMH said.

Eight people in the cluster attended Avalon Beach RSL on December 11 and 16 people attended the Avalon Bowlo on December 13. There were two people who attended both of these venues on these dates.

Dr Chant said people who were at the venues on these dates should have been contacted by NSW Health, and it was essential they come forward for testing and self-isolated.

The NSW CHO said the current situation was linked to a traveller from the US.

“The genome sequencing has determined the strain that gentleman acquired was most likely a US strain,” she said.

Premier says brace:

NSW Premier Gladys Berejiklian said the people of the state of NSW should “brace themselves” and expect more cases.

“The number of people who were at the (Avalon) RSL event on December 11 and then the (Avalon) bowling club on Sunday were substantial and obviously they have got household contacts and contacts of theirs,” she said.

Other states are now putting in place restrictions on travel from NSW.

WA is ordering people arriving from Sydney to quarantine at home for 14-days, Victoria and Qld are considering similar measures.

People from Northern Beaches of Sydney are being told to stay in place and not to travel for Christmas.

More from our earlier story.