Sources at major banks say they’ve traced patterns of fraudulent debit and credit card charges to accounts that have been used at Trump Hotel Collection resorts since at least February. Affected locations include Chicago, Honolulu, Las Vegas, Los Angeles, Miami, and New York.

The company has yet to confirm the reports.

In the last couple of years, major retailers like Home Depot and Target have suffered customer credit card breaches, while hotel chain Mandarin Oriental disclosed a compromise just this March and hotel franchise White Lodging admitted that card processing systems at several of its locations were breached for the second time in 12 months.

To help prevent breaches, more and more banks are switching to credit cards with chips instead of magnetic strips, which are presumably harder to hack. Retailers however, are still struggling to prepare for the switch, having delayed equipment implementations.