Residents of Western Australia have been urged to not rush the shops after chaotic scenes on Sunday afternoon in the wake of the state government lockdown announcement.

The five-day lockdown for large parts of the state came after a quarantine security guard tested positive for COVID-19.

After a 10-month coronavirus free streak, health officials moved swiftly,  with widespread restrictions on businesses and public events and an extension of school holidays.

The Premier Mark McGowan urged people to “be sensible and do the right thing”, asking the community to show calm and not rush to the shops – a message that appears not to have been heeded as mask-less locals sought to get in supplies.

Tweet from @DiWebster

The lockdown came into effect in Perth, Peel and the South West from 6pm until Sunday until 6pm Friday – just as the nation had gone two-weeks without any community transmission.

There is concern that the quarantine worker, aged in his mid-20s, may have come in contact with people in quarantine who have the highly contagious UK variant.

Mr McGowan said the man’s three housemates had so far testing negative and while he had a second job as a ride-share driver, he apparently had not worked in the time he was thought to be positive.

“His last day at work in [the] hotel (Four Points Sheraton) was Wednesday,” the Premier said. “So he worked in the hotel on the 26 and 27 which is Tuesday and Wednesday. We suspect he contracted the illness on the Tuesday or the Wednesday.

“So he went to the doctor and then he got COVID tested and we got the results last night. So we put in place a saliva test as quickly as we could, using the Health Department and appropriate protocols.”

Lockdown: The Four Points Shereton hotel where the outbreak originated. Photo: AAP

Mr McGowan defended the state’s record on virus mitigation, despite the lessons learned from Victoria where the virus escaped from hotel quarantine.

“Well, we have worked to address that,” Mr McGowan said. “But it has been a difficult system to resolve, because essentially, you know, you rely a lot on trust.

WA Premier Mark McGowan has acted quickly after the outbreak. Photo: AAP

“Because if people do an odd shift here or there, or elsewhere, it is hard to police that. We have been working on what protocols and arrangements we can work in place around that for some period of time, but it has been a hard period to resolve.

In any event, in the case of this person, the advice I have is that he has not worked a second job since he contracted the virus.”

Health Minister Roger Cook said contact tracing was underway.

“It is under investigation, obviously because something did go wrong and we do need to get to the bottom of it,” Mr Cook said.

“At this point in time we are investigating the current active cases in the hotel and undertaking genomic sequencing of those cases and that will be known in the next 24-48 hours and obviously do genomic sequencing on the individual himself.

“Once we have those details we will have the opportunity to provide you, or provide ourselves with further insights into where the gentleman contracted the disease, what variant or strain he contracted it from and in the context of that, what was the date.

Tweet from @ScottMorrisonMP

“Just for clarity because people are wondering if they do or don’t go to work tomorrow. If you are in one of the big high-rises in the city or the public service, do you go to work or do you stay home? You only go to work if you are considered essential to the operation.”

Mr Cook conceded there was concern that the Uk variant would be an issue.

“The reason why we are particularly interested around the UK variant is because we know he was on the floor with an active case, we do not know if that is the active case that he courted from or if it is from some other interaction in the work place full did he say if he went into a room?

“We know he did not go into a room and he did not expose himself unnecessarily and as a result of that we will undertake necessary investigations. This is obviously a very fresh situation and we are trying to get to the bottom of it.”

Western Australia’s lockdown rules

• Perth Metropolitan, Peel region and South West region in a five-day lockdown from 6pm on Sunday.

• People must stay at home unless shopping for essential supplies such as groceries, attending to medical or healthcare needs, exercising with one other person for up to an hour in your neighbourhood or attending work if working remotely is not possible.

• No visitors allowed in homes unless caring for a vulnerable person or in an emergency.

• Schools that were due to resume on Monday will remain closed for another week.

* Pubs, bars, clubs, universities, TAFEs, gyms, indoor sporting venues, playgrounds, skate parks, outdoor recreational facilities, cinemas, entertainment venues, casinos, places of worship and libraries all required to close.

• Restaurants and cafes to provide takeaway service only.

• Weddings banned. Funerals limited to 10 people.

• Masks to be worn at all times outside of home, including at work, on public transport and while exercising.

• People should not leave Perth, Peel or the South West during this period.

• Others can enter those regions only to access or deliver essential health and emergency services, or other essential needs.

• Non-residents currently in the affected areas must remain in place until the lockdown ends. Those who must leave for emergency reasons must return home immediately, stay home and get tested if symptoms develop.

* No visitors to hospitals, residential aged care or disability facilities unless there are exceptional circumstances.

• Category 2 and 3 elective surgery and procedures suspended from Tuesday February 2.

• Category 1 and urgent Category 2 surgery to continue.

-with AAP