ACT Health advises against travel to Northern Beaches as cluster balloons

Ms Berejiklian emphasised the importance of containing the outbreak over the next three days, but did not rule out further restrictions if more people tested positive.

Canberrans have been told not to travel to Sydney's Northern Beaches and anyone who recently returned must self-isolate, as the cluster tripled to 17 cases overnight.

if we get in top of this in the next 3 days we can get back to a normal Christmas..... but if not we may move to more restrictions

Other states have started tightening their borders with NSW, although mostly the restrictions apply to people who have been in the Northern Beaches area. WA, though, will force anyone coming from the state to quarantine for two weeks.

ACT Health issued a warning late on Thursday that any Canberrans who had been in the Northern Beaches area from Friday, December 11, needed to immediately self-quarantine and get a COVID-19 test.

All ACT residents have also been advised not to travel to the Northern Beaches at this time.

It came as NSW announced 17 cases were linked to the growing cluster, a spike from six reported just hours earlier.

NSW Premier Gladys Berejiklian has said the cluster has been sourced back to an international case.

"Somehow that's obviously gotten out into the community. The original source is an overseas strain and the genomic testing will give us more details, I'm hoping later today," the Premier told the Nine Network on Friday morning.

She said more cases linked to the cluster would be announced later on Friday, amid concerns infectious people could have visited other parts of Sydney without knowing they had the virus

ACT chief health officer Kerryn Coleman said this was difficult and "unsettling" news so close to Christmas.

She said as the situation unfolds further advice may be issued but is currently only extended to people who had been in the area of concern and not if Canberrans had guests from Sydney.

Several more cases and locations are expected to be added by NSW health authorities when the premier provides an update at 11am.

"Unless there is wider extent beyond the Northern Beaches I don't anticipate the advice [in the ACT] changing until at least Monday," Dr Coleman said.

She said health authorities would not be meeting flights arriving in Canberra from Sydney as residents in the affected area have been told to stay at home.

"However, it is important we act quickly to respond to this outbreak while NSW continue with their contact tracing and assess the extent of the local transmission that is occurring," Dr Coleman said.

"This is a timely reminder that as we make plans to come together with our family and friends in the coming weeks, or travel over the summer holidays, we must be COVID-Safe and get tested, even with the mildest of symptoms."

States are starting to enforce border restrictions for anyone travelling who was in the northern beaches region since December 11. Victoria, Queensland require people from the northern beaches region to quaratine for 14 days in their home or accommodation.

Western Australia will force all travellers from NSW to quarantine for two weeks.

Tasmania has closed its borders to anyone travelling from the northern beaches and and anyone travelling to the Northern Territory will need to undertake mandatory quarantine in either Alice Springs or Darwin.

Residents of the northern beaches council area will spend the weekend at home, as NSW health authorities asked them to not leave their house for three days.

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NSW Premier Gladys Berejiklian said the community should "brace themselves" ahead of the case announcement on Friday morning and called on Sydney residents to take up mask wearing.

She said the genomic testing had revealed the virus strain had come from overseas, but it was not known how it got out into the community.

"We are going to definitely have more cases today," she told Nine's Today on Friday morning.

She said Sydney was in a state of high alert and all residents should be wearing a mask in high-risk areas including public transport, places of worship and at the supermarket.

"We may have been in contact with someone from the Northern Beaches ... we're also concerned that some people who may have had the virus people on the Northern Beaches may not know it, may have been infectious and not known it, may have been infectious while they visited other parts of Sydney."

Authorities have identified two "super spreader events", one at the Avalon RSL on December 11 and one at the Avalon Bowling Club on December 13 and 15.

Anyone who has been in an affected location identified by NSW Health should contact the ACT Communicable Disease Control team on (02) 5124 9213 for further advice.

State and health leaders had an emergency meeting late on Thursday with most jurisidictions reimposing travel restrictions just a week before Christmas.

As of Friday, anyone who enters Western Australia from NSW must enter two weeks of quarantine. Anyone who arrived in the state after December 11 must get a COVID-19 test and isolate until they get a negative result.

Queensland also tightened its border rules and from 1am on Saturday will require anyone arriving from the Northern Beaches to complete 14 days in hotel quarantine at their own expense.

Anyone who has travelled to the sunshine state from that area since December 11 must also get tested and quarantine in their home or accommodation from the day they left.

Tasmania has locked-out anyone coming from the Northern Beaches unless they are an essential traveller.

Victoria has urged anyone who has been in that part of Sydney since December 11 to stay at home and get tested.

"They should stay at home until results are available and especially avoid visiting aged care facilities and hospitals," the health department said in a statement.

If you have been to these locations immediately self-isolate until 14-days after you were last there and get tested even if you have no symptoms.

Avalon: Avalon RSL Club, Friday December 11, all day until close.

Avalon Beach: Avalon Bowlo, 4 Bowling Green Lane, Sunday December 13, 5pm to 7pm and Tuesday December 15, 3pm to 5pm.

Avalon Beach: Bangkok Sidewalk Restaurant, 1/21-23 Old Barrenjoey Road, Monday, December 14, 7pm to 8pm.

Avalon Beach: Barramee Thai Massage and Spa, 4/42-44 Old Barrenjoey Road, Monday, December 14,2pm to 3:30pm.

Avalon Beach: Sneaky Grind Café, Monday December 14, 9:30am to 11am.

Kirribilli: Kirribilli Club, Monday December 14, 12pm to 3pm.

Palm Beach: Palm Beach female change rooms (in toilet block with small change area at the swimming pool at the southern end), Sunday December 13, 9am to 9:15am.

Palm Beach: Coast Palm Beach Café, Barrenjoey Road Sunday December 13, 10am to 11am.

Penrith: Penrith RSL Club, Sunday December 13, 1pm to 6pm.

If you have been to these locations get tested and isolate until you receive a negative result and continue to monitor for symptoms:

Artarmon: Roof Racks World, 13/87 Reserve Road Tuesday December 15, 2pm to 2:30pm.

Avalon: Careel Bay Dog Park & Hitchcock Park, Barrenjoey Road, Wednesday December 16, 7:00am - 7:30am.

Avalon: Hungry Ghost Café, 20 Avalon Parade, Sunday December 13, 9:30am to 11am and Tuesday December 15, 9:30am to 11am.

Avalon Beach: Avalon Beach Post Shop, 45 Avalon Parade, Wednesday December 16, 3:30pm to 3:50pm.

Avalon Beach: Chemist Warehouse, 4/74 Old Barrenjoey Road, Monday December 14, 5:20pm to 5:25pm.

Avalon Beach: Commonwealth Bank, 47 Avalon Parade,Tuesday December 15,12pm to 12:15pm.

Avalon Beach: Mitre 10, 49 Avalon Parade,Tuesday December 15, 12pm - 12.20pm.

Avalon Beach: North Avalon Cellars, 4/3 North Avalon Road, Tuesday December 15, 6pm to 6:05pm

Avalon Beach: Oliver's Pie, Careel Shopping Village, 1 Careel Head Road, Monday December 14, 9am to 9:15am.

Avalon Beach: Surf Life Saving Club, December 13 to 15, 9am to 9:30am.

Avalon Beach: Woolworths, 74 Old Barrenjoey Road, Sunday December 13, 12pm to 5pm, Monday December 14, 5pm to 5:30pm, Tuesday December 15, 12pm to 12:30pm.

Dee Why: Dee Why Fruit Market, 33 Oaks Avenue, Tuesday December 15, 4:45pm to 4:55pm.

Dee Why: HongFa BBQ Restaurant, Tuesday December 15, 4:30pm to 4:45pm.

Mona Vale: Aldi Mona Vale, 13 Bungan Street, Sunday December 13, 12:45pm to 1:30pm.

Mona Vale: Bing Lee, Gateway, 1 Mona Vale Road, Monday December 14, 4:30pm to 4:45pm.

Mona Vale: Woolworths Mona Vale, 25/29 Park Street, Sunday 13 December,12pm to 12:30pm

North Narrabeen: Brot and Wurst, 1442 Pittwater Road, Wednesday December 16, 2pm to 2:05pm.

Palm Beach: Palm Beach Pool, Lot 1 Rock Bath Road, Wednesday December 16, 8am to 9am.

Palm Beach: Palm Beach Rockpool, Lot 1 Rock Bath Road, Monday December 14, 9:30am to 10:30am.

Peakhurst: Gannons Park, Forest Rangers FC, Little Rangers session, Friday December 11, 4:30pm to 5:30pm.

Train route: Roseville to Redfern, Monday December 14, 6:50am to 7:40am.

Train route: Redfern to Milsons Point, Monday December 14,11:20am to 11:45am.

Train route: Milsons Point to Roseville, Monday December 14, 3:15pm to 3:40pm.