Coronavirus testing in Victoria has gone up a notch, with people waiting hours to be tested, while a doorknocking "army" is targeting designated hotspots.

The surge in Victorians getting tested for coronavirus has prompted authorities to open an additional testing site.

The Melbourne Showgrounds will open at 1pm on Wednesday to Keilor Downs Secondary College students, teachers and parents only.

From Thursday, the showgrounds will be available to the rest of the public, Health Minister Jenny Mikakos said on Twitter on Tuesday night.

Keilor Downs Secondary College was closed on Monday for deep cleaning after a contact linked to a family outbreak in the suburb went to school for two days while infectious.

Premier Daniel Andrews apologised for the delays at drive-through testing sites at shopping centres, where some people have waited up to four hours to be tested while others have been turned away.

Victoria recorded 17 new cases of COVID-19 on Tuesday, bringing the state's total to 1864 and marking the seventh consecutive day of double-digit infections.

The new cases have more than doubled the state's active cases in the past week to more than 130.

Testing sites at Chadstone, Highpoint, Northland, Pacific Epping and Pacific Werribee shopping centres have extended operating hours to meet demand.

Meanwhile, the premier said an "army" of officials would begin doorknocking homes in designated hotspots Brimbank, Cardinia, Casey, Darebin, Hume and Moreland to ensure residents are adhering to government guidelines.

Information about the virus will also be provided in languages other than English following concerns COVID-19 messaging hasn't been reaching multicultural communities in those areas.

"There has been very deep engagement with localised communities, multicultural communities, multi-faith communities," Mr Andrews said.

Eleven of the state's new cases are being investigated.

One of the latest cases is a returned traveller in hotel quarantine, three were found in routine testing, and two are linked to a Keilor Downs extended family cluster.

A worker at a Coles distribution centre in Laverton is one of the two family transmission cases confirmed on Tuesday.

Meanwhile, Brunswick East Primary School and Keilor Views Primary School were closed after a student at each school tested positive.