BUCKEYE, Ariz. (AP) _ Inmates who have held two guards in a prison watch tower for six days let their hostages talk to negotiators Friday night in exchange for food.

Prison officials have revealed few details about the standoff, but said being able to talk to the guards _ one male and one female _ was a positive sign.

``We know our correctional officers are alive at day six. That is a measure of success,'' said Ivan Bartos, the Yuma prison warden who has been aiding corrections officials at the facility in Buckeye, west of Phoenix.

Earlier Friday, one of the two inmate holding the guards captive came out to the tower's observation deck and pulled in two coolers. Cam Hunter, a spokeswoman for the Department of Corrections, declined to say what was in the coolers.

``We've had on and off requests for food and drink. Some days they have not asked for anything,'' she said.

Hunter said the negotiations were going well. ``The only acceptable outcome for us is the correctional officers released safely ... They need to walk out of that building,'' Hunter said.

The inmates have held the guards hostage since Sunday morning at the Arizona State Prison Complex-Lewis in a tower believed to be stocked with weapons. Authorities have not discussed the inmates' possible motive and have not released any details on their identities or previous crimes.

Until the crisis is resolved, the other 4,400 inmates are in lockdown. Regular weekend visitation was canceled Friday.