SAN JACINTO (CNS) - Firefighters were working on Friday to extinguish hot spots from a large hay-bale fire at a dairy farm in San Jacinto. The fire was reported about 7:35 p.m. Thursday in the 2400 block of Ramona Expressway west of Highway 79, the Riverside County Fire Department said. About 100 of 500 hay bales were on fire at the dairy farm when crews arrived, the department said. "Fire personnel remain on scene as 250 hay bales burned throughout the night,'' the department said in a statement about 6:30 a.m. Friday. "One engine will be assigned today along with skip loaders by the property owner. No injuries to personnel or livestock.'' Photos of the blaze from the fire department showed heavy smoke and flames. The cause of the fire was under investigation.