The Hudson River Greenway is a popular route for cyclists looking to ride between nothern Manhattan and Midtown. View Full Caption DNAinfo/Nigel Chiwaya

WASHINGTON HEIGHTS — Police are on the lookout for a group of muggers that hid in the bushes and used trip wires to rob cyclists along a stretch of the Hudson River Greenway in Riverside Park, according to reports.

The muggers have struck twice since mid-August, NY1 reports.

On Aug. 24 they attacked a 40-year-old man who was riding his bike at 11:30 p.m. near West 177th Street, tripping him up with a rope strung across the path and punching him in the face. The man was not seriously injured.

The thieves made off with $500 in cash, the man's iPhone and his $1,500 bike, NBC New York reported.

They struck again on Aug. 29, attacking a 35-year-old man near West 173rd Street with a baseball bat and stealing his wallet, kindle, iPhone and $1,000 bicycle, NBC reported. The victim suffered injures to his back and shoulders.

The men are said to be in their 20s.

"That's scary," said Jonathan Geis, a cyclist who was riding through the park on Wednesday. "I hope cops come out because of that."

Geis, who lives in New Jersey and has cycled across the George Washington Bridge every day since February, said he rarely sees police officers in Riverside Park.

"There's a police car at 95th street, but that's about it."

Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS (8477) log onto the Crime stoppers website at WWW.NYPDCRIMESTOPPERS.COM or text 274637 (CRIMES), then enter TIP577.