Staff and residents at an aged care centre in Melbourne’s inner east are undergoing further testing for COVID-19 after two workers at the facility contracted the virus.

Two staff members at Lynden Aged Care in Camberwell were confirmed as having the illness on Tuesday, the health department said in a statement.

The fresh cases bring the number of coronavirus infections linked to the facility to three, with a resident diagnosed with the condition on May 19 while being treated at a metropolitan hospital.

The centre has been in lockdown since that first case was confirmed, with extensive testing carried out.

The diagnosed staff members were not identified as close contacts of the original case.

“The source of acquisition for these new cases remains under investigation and all potential sources of transmission will be explored,” a department spokeswoman said in a statement.

Health officials are working with Lynden Aged Care to ensure appropriate public health actions are being taken, including contact tracing, isolation, quarantine, cleaning and disinfection.

Resident transfers and new admissions will also be restricted and staff will work in separate areas.

A further round of testing of all staff and residents also commenced on Tuesday.

Victoria has 1610 COVID-19 cases in total, with 56 cases active, while the state’s death toll remains at 19.

About 400,000 Victorian students in prep to year 2 and years 11 and 12 returned to schools on Tuesday after a seven-week hiatus.

The government says it will examine lessons from the experiment in statewide home schooling.

Education Minister James Merlino flagged an independent analysis and a summit of education leaders in June to do just that.

Australian Education Union Victorian branch president Meredith Peace said learning from home has provided an opportunity to re-engage reluctant students and those positives shouldn’t be lost.

But she said remote learning has also amplified the challenges schools, kindergartens and TAFE schools face in addressing disadvantage among students.