LOS ANGELES (KABC) — Seven inmates were hospitalized Tuesday morning after a possible overdose incident at the Men’s Central Jail near downtown Los Angeles, officials said.

Shortly before 7 a.m., Los Angeles Fire Department firefighter-paramedics were summoned by L.A. County Sheriff’s Department staff to “assist seven persons (all believed to be inmates), who may have inhaled or been exposed to a yet to be formally identified substance within a jail facility,” the LAFD said in a statement.

All seven patients were transported to hospitals for further evaluation or required care, officials said. One is in critical condition and the other six were listed in serious condition.

“No escalating or off-site hazard has been identified,” the news release said.

Just before 3 p.m., seven custody deputies were also taken to hospitals as a precaution after experiencing symptoms potentially related to the possible overdose incident from earlier.

“Custody deputies were searching the dormitory housing area and inmate property before they repopulated the location when some of them started to experience some symptoms,” the Sheriff’s Department said in a statement.

All deputies were conscious and in stable condition.