A band of thieves who engage supermarket shoppers in conversation so that accomplices can steal wallets from grocery carts apparently is operating in Fairfax County and Alexandria, police said yesterday.

As many as 25 such thefts have occurred since the beginning of March in the two jurisdictions, and police think they may be the work of the same people. There have been no arrests.

The thieves generally prey on women who place their purses in their grocery carts while shopping, police said. One thief asks the victim where to find a certain product, or for help in reading a product label, claiming poor English or forgotten eyeglasses.

"Anything to get the person to turn around for 30 seconds," said Sgt. Ralph Stanley of the Alexandria Police Department. At that point, another thief takes her wallet, police said.

The thieves have been variously described as two men or a man and a woman in their 20s or 30s, according to police, and authorities have indications that four or five people may be involved.

Fifteen to 20 thefts have occurred around Fairfax, including the Rte. 1 corridor, McLean and Springfield, and about five incidents have been reported in Alexandria in the past month, police officials said.