The robbers, Hoyal said, meanwhile, broke the jewelry store cases and stole the jewelry inside before running away. The two were seen getting into a black sedan with duct tape on the driver's side window.
Hoyal said the 80-year-old suffered hip injuries while the 86-year-old suffered cuts to her face and hands. Both women were taken to a hospital in serious condition, he said. No one else was injured.
Authorities are searching for the men involved. One of the men is described as a black male about 6-foot-2, weighing about 280 pounds, wearing a black ski mask and brown sweatpants. The other man was about 5-foot-4, weighed about 130 pounds and was wearing a black ski mask, dark shirt and jeans.
Tuesday's heist marked the third northern Utah jewelry store robbery since November.
A November heist in Provo and a Dec. 23 heist in Murray remain unsolved.
A robbery attempt on Friday was thwarted when the jewelry store manager pulled his own handgun. Unified police arrested one suspect at the scene. At least one robber got away.