A medium-security men's prison in Springhill, N.S., is in lockdown, according to Correctional Service Canada.

In a tweet late Monday afternoon, it cited an "ongoing inmate disturbance" at the Springhill Institution as the reason for the lockdown.

At 10:33 p.m., Correctional Service Canada tweeted the disturbance had been resolved, but the lockdown remained in place.

Assistant warden Shannon Oickle said the facility went into lockdown shortly before 1 p.m. Monday.

She said 19 inmates were involved in the disturbance and one of the offenders had to be taken to hospital. The seriousness and nature of his injuries have not yet been disclosed, but his next of kin has been contacted.

During lockdowns, visits are not allowed and inmates aren't permitted to leave their cells. Oickle said anyone who planned a visit to the facility Monday should call and reschedule.