SPRINGHILL, N.S. -- Officials at a medium-security prison in Nova Scotia say a dispute involving more than a dozen inmates has been resolved, but that the facility remains in a lockdown.

Assistant warden Shannon Oickle says the restriction was imposed at about 1 p.m. Monday after 19 inmates banded together and refused to return to their cells at the Springhill Institution.

She says they were outside their cells as part of their daily routine.

Oickle says they went back to their cells at about 8 p.m. following negotiations, but she wouldn't reveal the reasons for their actions because the matter is still under investigation.

One inmate was injured and sent to a hospital off site, but has since returned.

Oickle wouldn't provide details on the nature of the injuries or when the lockdown might be lifted.