KABUL - Afghan and U.S. officials said Friday that a joint military operation has freed at least 40 Afghan security forces from a Taliban prison in the southern Helmand province.

A statement from U.S. forces in Afghanistan said that Special Forces from the two countries carried out a helicopter assault on the prison in Nawzad district Thursday night. The statement says the operation freed 40 prisoners, who were captured Afghan police, army and border police.

The Afghan defense ministry says 60 prisoners were rescued. The discrepancy in the number of prisoners freed could not immediately be explained.

The ministry said the original aim of the operation was to arrest a Taliban commander.

It was not yet clear how the prisoners were originally captured. (AP)