A lock-down was ordered for part of the California Institution for Men at Chino as officials investigated the cause of a weekend brawl that left several inmates injured. Preliminary reports indicate that the fight during breakfast involved black inmates against Latino and white inmates, prison spokesman John Dovey said. Handmade knives were wielded and several inmates suffered minor injuries, but none was hospitalized. Dovey said the lock-down kept 1,450 of the facility’s 5,000 inmates in their quarters. The prison is divided into four building complexes, each overseen separately.