A letter from the leadership at the Shrewsbury Colleges Group, seen by the Shropshire Star, confirmed that four students across the town's three campuses have tested positive.
Because of when the students were last in close contact with others and when they experienced symptoms, only three class groups have been affected.
The letter said: "I'm letting you know that we have had a further four confirmed positive Covid cases notified to us, all of which are students. The students have all reported the positive results to us this morning [Wednesday].
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"In three cases the students have not attended college during their initial 48-hour infection period, therefore there have been no close contacts identified within the college setting. This relates to two A-Level students at English and Welsh Bridges and one Health and Social L3 student at London Road.
"The staff and students from the groups have been contacted and informed that they are not close contacts and can continue to attend college after half term.
"In the fourth case the student did attend college in the 48 hours before they reported symptoms.
"The subjects affected are A-Level Geography, German and Mathematics. The student has provided information, we have consulted seating plans and we have spoken to their teachers.
"Following this, the students identified as close contacts have been notified and asked to self-isolate. No staff members are affected.
"We have again today contacted Shropshire Public Health regarding these four cases. They remain happy with our approach."