Police are warning residents of a group of people posing as “tree service workers” in southwest suburban Palos Park.

Officers stopped the group, posing as a crew of workers offering services for downed trees on Monday near 88th Avenue and 121st Street, according to Palos Park police.

The scammers were going door-to-door offering help with the removal of downed trees at a discounted rate if customers paid up front, police said. They would then take the money and leave without ever returning to remove the trees.

Police are warning residents to beware of services that require up-front cash payments and to expect written estimates and printed materials from legitimate tree services that are registered with the Village of Palos Park, police said.