Police are investigating an alleged home invasion and sexual assault in Crescentville early Tuesday.

A 24-year-old woman told police that about 3:50 a.m., an unknown man forced his way into her home on the 5100 block of Mebus Street, tied up her family and then sexually assaulted her at gunpoint.

The man was described as black, about 25 to 30 years old, 5-foot-6 and of medium build. He was said to be wearing blue jeans and a black mask, and had a silver handgun.