Health officials say 11 people have been hospitalized in intensive care after contracting a bacterial infection linked to a San Francisco Bay Area restaurant.

San Jose news station KNTV reported Monday that the Santa Clara County Public Health Department issued a warning to people who ate at Mariscos San Juan on Friday or Saturday. The restaurant had its permit suspended Sunday.

Officials say more than 40 restaurant customers have been sickened by an intestinal infection caused by the shigella bacteria. Symptoms include fever, abdominal pain and diarrhea.

Dr. Sara Cody, Santa Clara County’s health officer, says shigella can be spread by people who do not wash their hands after using the bathroom. It is treated with antibiotics.

Calls to the restaurant by The Associated Press rang unanswered Tuesday.