The FBI is investigating after needles were found in turkey sandwiches on Delta Air Lines flights from Amsterdam to the United States.

Delta says what appear to be sewing needles were found in five sandwiches Sunday. One passenger on a flight to Minneapolis was injured.

The other needles were on two flights to Atlanta and one to Seattle.

FBI Special Agent Stephen Emmett in Atlanta confirmed Tuesday that the agency is investigating but declined to comment further.

The Transportation Security Administration says it's closely monitoring the situation. The agency said it immediately notified U.S. carriers with flights from Amsterdam's Schiphol Airport.

The sandwiches were made in the Amsterdam kitchen of catering company Gate Gourmet.