Provo police Saturday were investigating two unrelated armed robberies in Provo Friday night, one at Brigham Young University and a second at a Center Street grocery store.

According to BYU officials, a man estimated to be between 18 and 21 took $590 in cash from the BYU after-hours convenience store The Twilight Zone at 9:30 Friday after brandishing an automatic pistol and demanding money from a cashier.BYU Public Communications Director Paul Richards said the robber was described as a 5 foot 6 inch white male, weighing approximately 130 pounds, with dark curly brown hair. He wore a red baseball hat with "Mamooth" written on it and had on dark glasses, a blue jean jacket and a white turtleneck sweater pulled over his face.

Richards said a second man, who apparently acted as a lookout outside the convenience store, was 6 feet 1 inches tall, had thick red-brown hair and wore dark glasses, a blue coat with a Canadian pin on it and a red, yellow and blue ski cap.

A second robbery occurred about an hour later at Reams grocery store, 890 W. Center. Provo police said the robber apparently walked through an unlocked door at 10:40 p.m. and demanded the night manager open the store safe.

When the night manager told the man he didn't know the safe's combination, the robber took an undisclosed amount of money from two cash registers and fled on foot.

The suspect, who brandished a semi-automatic pistol, is described as a 6-foot white male, in his late 20s, weighing 155 with dark hair and dark eyes.