The battle for mayor of Mount Vernon became heated on Saturday.

Democratic mayoral candidate Richard Thomas was about to begin a press conference announcing the endorsement of the local Mount Vernon firefighters when supporters of incumbent Ernie Davis began chanting, honking car horns and descending on the parking lot of the Mount Vernon firehouse.

Thomas is campaigning against the embattled mayor, who is running for a fifth term and is currently on probation after pleading guilty to federal tax evasion charges last year.

Thomas says that Davis is well known for trying to intimidate voters with those types of tactics.

"This is thuggery and this is the type of stuff we need to change in our city," he says. "This is what is holding us back and why Mount Vernon is frozen in time."

Supports of Davis say they that they disturbed the press conference because Thomas is using "tricks to advance his own political career." The supporters say they were upset about the location of the press conference, which was named after a firefighter who was a friend of Davis.

Voters will head to the polls for the primary election on Sept. 10.