A 19-year-old has claimed she also saw a masked intruder peer into the back of her house from the garden.

After a woman in her 50s told the Watford Observer about her “shocking” experience when a masked man looked into her home, another household recognised the "MO".

Four days before the “suspicious activity” in Gade Avenue at around 2pm last Friday, the teenager had been home alone when she saw the man creeping through her garden out of the corner of her eye, in Cassiobury Park Avenue, at around 2.30pm on August 7.

He was reportedly in his mid-twenties and wore a blue hoodie, skinny jeans, and a surgical face mask.

He apparently looked startled when she jerked the curtain but, just like in the other report, he stopped and waved at her. He then turned around and “briskly” walked across the garden and hopped over the fence into Cassiobury Park.

Gade Avenue and Cassiobury Park Avenue are around the corner from each other and both back onto Cassiobury Park.

In the Gade Avenue report, the woman had seen the man in a side alley she said could only have been accessed from the rear. He had looked into the kitchen window and waved when she saw him.

“He wasn’t supposed to be there, I was angry and shocked," she said. “I went outside to say 'what the hell are you doing' but he had vanished.”

Herts Police issued a description that said: “The man was described as in his twenties, around six-feet-tall with short, black hair, and of a lean build.

Watford Observer: A garden fence at the Cassiobury Park Avenue property, which the residents think the man may have climbed over.A garden fence at the Cassiobury Park Avenue property, which the residents think the man may have climbed over. (Image: Contribution)

“He was wearing a medical mask. The local policing team have been made aware and residents should report any similar incidents.”

The 19-year-old’s mother told the Watford Observer that her daughter noticed he also wore gloves.

The mum said she had expected other people might have seen the same thing.

“I thought it was probably someone thinking people are on holiday,” she added.

“I would have thought he would have tried other houses.”

Herts Police urged neighbours to report similar incidents.

Sergeant Brad Cross said: “We recognise that this is incredibly concerning for residents in the area, especially since this is the second reported incident of the same nature.

“We want to reassure residents that patrols have been increased within this area in light of these recent events. Officers and PCSOs will be conducting these hi-visibility patrols throughout all hours of the day.

“Work is also underway to ascertain who the suspect could be, and I would ask residents to ensure that anything suspicious is reported to police right away so that officers can respond appropriately.”