HOUSTON -

An 85-year-old man was robbed by two armed men at a Houston park.

The man says he was walking down the Terry Hershey Park Hike and Bike Trail near Dairy Ashford, in west Houston on Monday when he said two armed men who had their faces covered demanded his money.

"Saw this elderly man. Opened the door and he told me he had been robbed on the trail," said resident Scott Johnston. 

The victim went to Johnston's home for help.

"They were estimated to be about 20, although they had their faces obscured," said Johnston. "And they each had automatic handguns and they demanded his money and everything and they told him to walk away east and so that's what he did. My house happened to be the first one he came to."

Johnston said the thieves stole the man's iPhone and $40.

The Harris County Precinct 5 Constable's Office said there have been five serious crimes reported in the last month along the trail. They include a cyclist robbed in December, a woman raped last Friday after she walked into a park restroom at the trail on Eldridge and two robberies reported last weekend. 

Investigators said the same two attackers could be to blame for all of the crimes. The robbers in Monday's crime were described as two young black men standing about 5 feet 9 inches, who are 18 to 20 years old. 

In Friday's attack, the victim said one attacker wore a grey sweatshirt with a Rice University emblem. The other wore a black jacket. 

Officials with Precinct 5 said they are increasing patrols in the area.