A school in Melbourne's north will be closed for the rest of the week due to a year 5 student testing positive for COVID-19 and residents of surrounding suburbs are being urged to get tested if they have symptoms.

East Preston Islamic College's principal, Ekrem Ozyurek, said the boy stayed home from school last week, because his siblings had tested positive for coronavirus in recent weeks.

The boy came back to school this week and attended on Monday and Tuesday, after his mother brought a letter from Victoria's Department of Health and Human Services (DHHS) dated October 17 clearing the other children of having coronavirus.

But on Tuesday DHHS called the school and said the boy was supposed to still be self-isolating as he waited for a day-11 test.

Mr Ozyurek closed the school as a precaution, and on Wednesday morning DHHS informed the school the boy had tested positive for COVID-19.

Mr Ozyurek said there seemed to have been some confusion because the boy's parents said he had tested negative before this test.

"As school just got back we were thinking, 'Yes, we're back finally,' then this happened," he said.

"It happened to us today and it can happen to another person. It may not happen for two weeks and it could happen another week later — we don't know.

"So my view is that we have to put everything aside and find out a way of working together.

"We aren't blaming anybody."

Mr Ozyurek said the school had provided DHHS with a list of the boy's classmates and teachers for contact tracing.

The principal said the next step was waiting for DHHS's recommendations on when it would be safe to reopen the school.

"If everything is OK we'll be back to normal on Monday," he said.

Surrounding areas alerted

Late on Wednesday, DHHS urged any residents of Melbourne's northern suburbs including Dallas, Roxburgh Park, Broadmeadows, Preston and West Heidelberg who are experiencing symptoms to be tested for coronavirus.

"The College has taken positive steps to manage this situation and is working closely with us. It has been closed for deep cleaning," commander of testing and community engagement Jeroen Weimar said in a statement.

"We need everyone working together to tackle this virus, and that's exactly what the school community is doing.

"Staff and students who are close contacts — and their households — have been identified and are quarantining for 14 days."

A text message was sent on Wednesday afternoon alerting people who lived in or were visiting the listed suburbs and surrounding areas to get tested if they experience symptoms.

The DHHS statement said other cases had also been identified in a social housing block in Broadmeadows.

Advisory notices have been issued to 120 residents asking them to self-isolate for 48 hours, get tested and monitor for symptoms.

A close contact has also been identified at Dallas Brooks Primary School, which has been closed for deep cleaning.

DHHS said an extensive community health door-knocking program would start on Thursday morning to alert residents in identified areas about potential exposure to coronavirus, where to get tested and how to access support, such as financial assistance.

Pop-up testing sites were being organised and rapid response testing at home was made available for those who could not attend a testing site.