Dr Sakthi Karunanithi, director of public health for Lancashire County Council, said it is "vital" that everyone within the college community gets tested for Covid-19 "as soon as possible".
It comes after a spike in cases led Runshaw College to immediately shut down its campuses in Leyland and Chorley under advice from Government health advisers.
More than 30 students are believed to have contracted the virus, including a "small number" who have tested positive for the Indian variant.
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The college will shut for 10 days from today, before reopening on May 17. You can read the full statement from Runshaw College here.
Dr Sakhti says it is "crucial" and "vital" that those at the college get tested in order to "isolate the virus and break the chains of transmission".
He said: "We've been working closely with Runshaw College and Public Health England following a spike in Covid-19 cases among staff and pupils.
"A small number of cases may be linked to a case of the Indian variant that has been found elsewhere in the region. We are awaiting further information on this.
"Subsequently, a decision has been taken by the college, with our full support, to temporally close and switch to remote learning.
"During this time it is vital that pupils, staff and their households get a PCR test as soon as possible so we can isolate the virus and break the chains of transmission.
"You can order a PCR test kit to be sent to your home or book an appointment at a walk-in or drive-through test site.
"If you have symptoms, you and everyone you live with must immediately self-isolate and leave only to post a test kit or for a PCR test appointment.
"It is crucial that people follow these rules so we can stop the virus from spreading further.
"We will continue to support Runshaw College over the coming days and will work closely with them to develop a plan for a safe reopening."
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