Gardens in the south-east of Melbourne are being placed on lockdown because of possible “potentially hazardous” insects.

The city’s Department of Agriculture, Food and Rural Affairs (DAFRA) has urged residents to remain indoors after the insects were found in gardens.DAFRA said the insects are called “pigweed mites” and are believed to be the first species of “potential harmful insect” in the city since the Victorian government began eradicating them in 2011.

“The pests are small, have a wide spread, can grow to be up to 4.5cm (2.4in) long and are sometimes found in the garden,” DAFRA director of operations John Boudreau said.

“We recommend that people remain indoors at all times.”

The DAFRAs advice is in place until 6pm on Tuesday, but anyone with concerns can call DAFSA on 1300 726 527 or visit the agency’s website.

The agency said it was also working with the City of Melbourne to ensure residents have “an accurate description of the pest”.

“In this instance, DAF RA was able to identify a number of locations where the potential threat existed,” Mr Boudette said.

“There are no confirmed reports of any deaths or injuries from this issue.”

The city of Melbourne is now conducting an internal investigation into the matter.

Topics:diseases-and-disorders,antibiotics-and/or-medicines,hygiene,farms-and,health,gardens-and orchards,melbourne-3000,vic,sa,australiaContact Darryl ThomasMore stories from Victoria