MONTREAL -- Montreal public health officials are urging Montrealers to cut back on social gatherings and show more vigilance when they do take part in social activities, as the city moves into the "yellow" COVID-19 alert zone.

Public health officials announced Tuesday that 96 more people have tested positive for COVID-19 on the island in the past 24 hours for a total of 30,571. There were no new deaths in the same time period, and the total number of people who have died due to the disease remains at 3,476.

Montreal public health director Mylene Drouin said in a news conference that they are not closing any sectors at the moment, adding that private social gatherings -- both large and small -- are mostly to blame for the increase in cases.

COVID-19 is spreading more quickly among young people ages 18 to 30, said Drouin.

"Don't invite 10 or 15 people over, let's not do that now," said Drouin, adding that anyone who takes part in a social gathering, be it a dinner among friends or an organized event like a wedding, should not loosen up on health guidelines. That includes physical distancing of two metres, washing hands frequently, and when the two-metre distance isn't maintained, to wear a mask.

Moreover, think twice about going at all, said Drouin.

"If it's not essential to go to that gathering, don't go," she said.

Drouin said public health workers are also facing difficulty with contact tracing. Those exposed to the virus either aren't answering their phones or are not cooperating with public health workers to help track the spread.

It's clear, said Drouin, that people are loosening up on distancing measures, because in March, public health workers were seeing 10 contacts per person, now it's as high as 80 per person.

"It is quite a big burden and it is one of the reasons I'm asking people to reduce their contacts and that they do keep the two metres," said Drouin, adding that children going to school now further widens those contacts.

Drouin said anyone who is experiencing symptoms, came into contact with someone who tested positive, or attended a gathering were distancing guidelines were not in place, to get tested.

There are 25 public retirement home (RPA) and long-term care facilities (CHSLD) with at least one confirmed case of COVID-19.

There are also 24 outbreaks in workplaces, said Drouin.

Montreal North has reported the highest number of positive cases with 2,712, followed by Ahuntsic-Cartierville (2,540 total) and Mercier-Hochelaga-Maisonneuve (2,539 total). Montreal North also has the highest rate of infection at 3,219.6 people per 100,000 followed by Riviere-des-Prairies-Pointe-aux-Trembles with 2,145.3 people per 100,000 (2,290 total cases).