BILLERICA (CBS) – A Chipotle in Billerica has been shut down temporarily after an employee was diagnosed with norovirus and two others reported similar symptoms.

By late Tuesday, cleanup crews had arrived with sanitation supplies in tow. Customer after customer arrived to find a familiar sign on the door.

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“Disappointed they’re closed again,” said customer Tim Wood.

The Chipotle in Billerica voluntarily closed earlier in the day after four employees called out sick. One of those employees tested positive for norovirus, two others are suspected to have the virus. Cases among customers have not been reported.

The Board of Health was immediately notified and work began.

“I think the restaurant is doing everything possible to sanitize and bring everything back to a cleanliness state to reopen,” said Sandra Giroux of the Billerica Board of Health.

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But that might not happen until the end of the week at the earliest and those infected employees won’t be allowed back to work until their symptom-free for five days.

“They’re a great company, we love them,” said customer Connor McCarthy. “We come here all the time. I haven’t had any problems with it, I’m sure they’re just looking out for us.”

Health inspectors will be at the restaurant Wednesday morning.

In December, the Cleveland Circle Chipotle was closed for several weeks after more than 150 people became sick after a norovirus outbreak.

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At a February all company meeting, Chipotle urged employees to stay home if they feel sick.