Northern Ireland's Maghaberry Prison has been closed to visitors today to allow a surpirse search for drugs in the top security facility.
The two prison buildings - Foyle House and Lagan House - contain non-paramilitary inmates and it was believed the searches were mounted after the Prison Service received intelligence indicating drugs may have been smuggled into the jail.
A spokesman said the searches were "part of our ongoing drugs strategy."
Inmates were understood to have been locked in their cells for the duration of the searches.