Joe Biden’s top-secret itinerary was found in a street in Belfast, Ireland, raising security concerns, according to the Police Service of Northern Ireland (PSNI).

A document that showed where Biden was staying in Northern Ireland, along with phone numbers of senior PSNI officers, was found on the street, the Irish Examiner reported Wednesday.

Biden departed the United States to Ireland on Tuesday with his sister, Valerie Biden Owens, and son Hunter Biden. The family landed at Belfast Airport on Tuesday evening and proceeded to meet with British Prime Minister Rishi Sunak on Wednesday.

The PSNI told the Examiner in a statement it is “aware of a security breach” and that an “investigation has commenced and we have notified the Senior Information Risk Officer.”

“We take the safety of visiting dignitaries, members of the public and our officers and staff extremely seriously and will put the appropriate actions in place,” the statement read.