BOSTON – Charred pieces of mail were discovered inside a U.S. Postal Service mailbox in Boston’s Copley Square late Monday afternoon not far from where a fire was set inside a ballot drop box on Sunday.

Boston police and Postal Service personnel were seen investigating the mailbox, which is located near the CVS Pharmacy at 607 Boylston St.

Boston police Sgt. Det. John Boyle confirmed that burned mail was found inside the mailbox. Police are leading the investigation, he said.

Boyle said police could not yet confirm whether the mailbox fire was related to the fire in the ballot drop box.

Police arrested a man Monday in connection with the fire set in the ballot drop box outside of the Boston Public Library’s main branch. That fire was set around 4 a.m. Sunday.

The suspect, Worldy Armand, 39, appeared in court Monday. Both the defense and prosecution agreed that he has mental health issues. More at WCVB