GRANITE, Okla. (AP) -- A two-day search at the Oklahoma State Reformatory in Granite uncovers about 20 homemade knives.

The sweep came just days after 29-year-old David Ray Jones Junior was stabbed to death during a fight between groups of black and white inmates. He's the third inmate to be killed by another inmate this year and the second to have been stabbed.

Corrections officials say they've seen an increase in the number of inmates being written up for having weapons.

Officials say they're investigating the latest stabbing and trying to determine what it might mean for the system.

The warden at Granite says the reformatory is still in lockdown and that she expects the high alert to continue for a couple of weeks.