According to Chicago police, several women allegedly entered the hotel at about 6:45 a.m.and began putting "unknown objects" onto tables that held the food. They then left the area, police said.

It wasn't immediately known if any of the delegates consumed the food, but police said one person was treated and released at the scene.

The hotel released a statement, saying in part, "We can confirm that a group of individuals caused a disruption at a DNC-related breakfast event at our hotel this morning. We are grateful for the swift response of law enforcement. The safety, security, and well-being of our guests and staff are our top priorities."