A Concord deli has been closed by Contra Costa County environmental health officials due to norovirus contamination.

The Concord Patch reports Marilyn Underwood, environmental health department director, said the North Park Deli on Nelson Avenue was shut down late Tuesday afternoon. It’s uncertain when the eatery will re-open.

Underwood said two employees at the deli have tested positive for the virus.

She said her department was first notified of the illness when 15 people who were at an event catered by North Park Deli on Friday evening became sick over the weekend.