NEW CANAAN, Conn. (AP) — More than 350 students and 20 teachers in a wealthy Connecticut suburb are in quarantine after a new round of coronavirus testing turned up 15 infections, according to the local school district.

New Canaan schools on Tuesday reported 13 students and two teachers tested positive, days after all 540 COVID-19 tests of students came back negative, the Stamford Advocate reported. There were also 26 new positive tests last weekend, First Selectman Kevin Moynihan said.

“We continue to see cases spread from gatherings, dinner parties, out-of-town caregivers, house cleaners, and not unexpectedly, within families,” Moynihan said. “This rapid case increase over the weekend illustrates how fast community transmission spreads and accelerates.”

The most recent testing resulted in quarantines for 213 students at New Canaan High School, 70 at Saxe Middle School and 70 at three elementary schools. People in quarantine are told they must stay home for 14 days.

The new test results come as virus-related infections, hospitalizations and deaths in Connecticut are increasing.