Leavenworth ? Inmates at the U.S. Penitentiary in Leavenworth are being allowed out of their cells but must remain in their housing units as a lockdown started on Saturday continued.

Prison spokesman Thomas Sheldrake says the inmates were able to get out of their cells Wednesday to have access to showers, phones and email.

The lockdown began after three fights in one housing units and two large groups assembled in the recreation yard. The fights were quickly contained and only minor injuries were reported.

The Leavenworth Times reports Sheldrake said the incidents apparently were isolated events.

The lockdown is in effect only at main prison. Normal operations continue at the nearby prison camp.