(Reuters) - Louisiana authorities on Monday were searching for three inmates who scaled razor wire fencing to escape from a medium-security prison, the local sheriff's department said.

Michael Elliot, 24, Walshea Mitchell, 35, and Willie Ethridge, 34, broke out of the Natchitoches Parish Detention Center at about 10 p.m. CDT on Saturday night, the Natchitoches sheriff's office said.

Elliot was serving a sentence for theft, Mitchell for armed robbery with a weapon and attempted armed robbery, and Ethridge for attempted second degree murder and armed robbery.

The men are not believed to have been armed at the time of their escape, the sheriff's office said.

The trio apparently scaled two rows of fencing topped with razor wires to flee the prison, which houses some 550 minimum- and medium-security adult male inmates, the sheriff's office said.

(Reporting by Laila Kearney; Editing by Jeffrey Benkoe)