CLEVELAND -- Police are warning northeast Ohio residents about fake water workers scamming their way into homes and robbing homeowners.

Police said there have been at least three incidents in the past week, in Cleveland, Mentor and Walton Hills.

In one case, an elderly couple was found locked inside their home, and investigators believe all three may be related.

In the Cleveland case, police are searching for five men who posed as water department workers, robbing the elderly couple of $100.

Michael and Adela Fronczyk are in their 80s and speak little English. On Thursday morning, while working in their back yard, they became the targets of the fake workers.

"My grandmother is all shook up. She's still upset," said the victims' granddaughter, Jen Blaut.

Police said when one of the men lured Michael into the basement to check the water, the others came in.

The robbers rummaged through the home and found Adela's purse, stealing $100 and some gift cards.

John Goersmeyer of the Cleveland Water Department said all of their employees wear ID badges that are visible at all times.

They also have uniforms shirts with water department logos on them, and they will be driving a white or blue vehicle with the same logo on the side.

More importantly, he said the workers won't show up unannounced.

"We never go to your house unless you make an appointment to come and provide some sort of service," Goersmeyer said.

Real employees don't have to enter your home to read a meter. If you are still uncertain, call the water department to verify the person's identification.

The number is 216-664-3130.