The search for missing plastic containers used to store food has forced a maximum-security prison near Kingston, Ont., into lockdown.

Millhaven Institution is a maximum-security prison outside Bath, Ont. It took over for Kingston Penitentiary, a 178-year-old building that closed last September. (Google Earth) "The search was ordered to ensure the safety and security of the institution, its staff and inmates," Correctional Service Canada said in a media release Monday about the Millhaven Institution.

"Normal operations will resume as soon as it is considered safe to do so."

The lockdown was ordered at Millhaven — the prison built to replace Kingston Penitentiary — on Sunday at about 7 a.m. ET.

The missing containers are used to store food items such as cereal, said Vicki Willis, an assistant warden at Millhaven.

Regularly scheduled visits may be affected by the lockdown and visitors are asked to call the institution directly before travelling there.