The three teenage boys all live close to the nearby town of Béziers, reported Le Parisien newspaper on Thursday.
Driving a stolen Renault Clio, the boys roamed around the area targeting women who were alone in the street.
They threatened the women with knives and screwdrivers and made off with handbags, purses and jewellery.
An attack on Sunday brought the three to national attention after they tried to snatch the handbag from a 73-year-old woman.
The woman resisted, apparently because her reading glasses were in the bag, causing the boys to push her to the ground. The woman was shaken but not seriously hurt.
Police finally caught up with two of the boys while the third is still on the run.
"We're dealing with a series of robberies using the threat of weapons," said the Montpellier prosecutor, Brice Robin.
"These acts are sufficiently serious that they are being held in prison."
The boys are also suspected of having burgled at least four houses on New Year's Eve.