CTTransit says it is dealing with a cybersecurity incident.
A spokesperson for parent company First Transit said computerized phone lines and email are currently offline. Bus service has not been affected.
"CTTransit is currently experiencing a computer and communications disruption following a detected cybersecurity incident. The affected systems were immediately quarantined and taken offline, and a full investigation is currently underway to determine scope and impact of the situation," a company spokesperson said in an email to NBC Connecticut.
CTTransit is asking passengers to call CT Rides at 203-624-0151 in Hartford and New Haven, and 203-327-7433 in Stamford with any service questions until the situation is resolved.
More details were not immediately available.