A northern New England cafe chain is working with authorities investigating the theft of customers’ debit and credit card information. The Brattleboro Savings & Loan warns on its website that it has seen a sharp increase in fraudulent debit card transactions and believes there’s been a breach at The Works Bakery Cafe. The bank says accounts may be compromised if customers have used debit cards at any of the chain’s locations. According to its website, The Works is based in Keene, N.H., and has cafes in Brattleboro and Manchester, Vt.; Keene, Portsmouth, Durham and Concord, N.H.; and Portland, Maine.