Police are looking for a suspect posing as a UPS worker and an accomplice who allegedly made off with more than $40,000 cash after an armed home invasion in Manhattanville.

Authorities say the UPS imposter knocked on the door of an Amsterdam Avenue home at 10:30 a.m. Monday and when the victim opened it, the fake parcel service worker and another man pushed their way inside.

At least one of them had a gun, police said.

The suspects tied up three people in the home and proceeded to look for cash. About $28,000 in cash was taken from a safe, another $12,000 was stolen from a dresser and $500 was taken from a pants pocket, law enforcement sources said.

The men then fled the home, got into a silver Nissan and fled westbound on West 133rd Street.

A UPS employee tells NBC 4 New York that such impersonators make it difficult to do his job. 

"He makes me look bad. When I come inside the building, they don't want to open the door because they think it's somebody else," the UPS worker said.

Leroy Smith, a neighbor, said he was glad no one was hurt. But looking through the peephole and seeing someone who appears to be in an official uniform doesn't necessarily mean it's safe to open the door, he says.

Another neighbor, Yvette Otey, said she frequently stays with her 87-year-old father in the building and the nearby home invasion has her on edge.

"If I'm not expecting a package, I'm not opening my door," Otey said.

The suspect who appeared to be wearing a UPS uniform is described as being about 20 to 30 years old, 5 feet 11 inches tall and 190 pounds.

The second suspect is said to be about the same age, weight and height. He was wearing sweatpants, a gray hooded sweatshirt, a baseball hat with a gray brim and white sneakers. Authorities say he was carrying a black backpack at the time of the robbery.  

Anyone with information about the home invasion is asked to call Crime Stoppers at (800) 577-TIPS (8477).