The Middlesex-London Health Unit (MLHU) has declared a COVID-19 outbreak inside a residence building at Western University.

Health officials said Thursday afternoon that eight people from Saugeen-Maitland Hall have tested positive for the virus and are currently self-isolating at an undisclosed location off campus.

"This outbreak highlights the need to limit close contact to only those within your dorm room, maintain two metres physical distance from all others, wear a mask in all indoor public spaces and stay in your room or suite if you feel unwell," said Dr. Chris Mackie, the medical officer of health with the MLHU.

"Declaring an outbreak is an important step in order to limit further spread of the virus within the student community," he added.

The traditional-style residence, located just a few blocks northwest of main campus, mostly houses first-year students. Due to the pandemic, capacity in the building was reduced to allow one occupant per room.

At this time it's unknown if those infected are from the same floor or if the virus has spread across the entire building.

"A big chunk of students have been tested already. We'll been testing everyone in that building," Dr. Mackie told CBC News.

Western University said those who have tested positive as well as some of their close contacts have been moved to a quarantine location.

"We are supporting students who have tested positive with transportation, meals, access to medical and mental health support as needed, and academic accommodations as necessary," said Chris Alleyne, the school's associate vice-president of housing and ancillary services.

The MLHU said it's following up with all close contacts to ensure they get tested and quarantine.

Last month, Western's London Hall was the first to have an outbreak after four students living in the building tested positive for the virus.

This week, 25 people under the age of 30 have tested positive for COVID-19 in the London region.