A trio of robbers followed an elderly woman onto a Brooklyn bus — and then made off with the cash in her fanny pack, police said.

The 72-year-old victim was at the Kings Plaza Mall in Mill Basin on Jan. 15 about 4:30 p.m. when the man and two women began following her, cops said. The three suspects then followed the woman onto a bus, which eventually dropped all of them off, including the victim, at the intersection of Flatlands Avenue and East 80 Street, authorities said.

The male suspect, described wearing a red hat and a sweater with the word ‘Brooklyn” on it, then tore off the victim’s fanny pack and grabbed the $200 inside, cops said. The gang fled with the cash on foot, according to police.