Authorities are offering up to a $50,000 reward money information leading to the arrest of the robbers who held up a United States Postal Service mail carrier in west suburban River Grove on Tuesday.

The robbery occurred about 9:30 a.m. in the 8700 block of West Richard Street, according to the United States Postal Inspection Service.

One suspect was described as a Black male, 5 foot 6, with a thin build, USPIS said. He was wearing a light-gray hooded sweatshirt and black facial covering.

Postal inspectors believe there were four people involved in the robbery. They fled the area in a silver Hyundai sedan and were considered armed and dangerous.

Anyone with information is encouraged to call the U.S. Postal Inspection Service at (877) 876-2455. The case number is 3681116.