BOSTON -- A mistake in an order turned violent at a Quincy McDonald's this week when an employee gave two customers a small order of french fries instead of a large, police said.

Christina Galipeau, 22, and Eugene Jackson, 33, both of Boston, allegedly began hurling coins and plastic safety cones at cashiers in the North Quincy restaurant on Tuesday, the Patriot Ledger reported. One person was injured.

A cashier who took the couple's order told police that when Galipeau complained of getting the wrong size fries, she gave her a large fries and handed her change.

The women exchanged words and the cashier said Galipeau threw the change at her, hitting her in the face, the paper reported.

Jackson then allegedly picked up a 2-foot-tall cone from the mopped floor and hurled it at the cashier and another employee, a 54-year-old woman, police said.

Both pleaded not guilty to assault charges at their arraignment in Quincy District Court.

It is the second incident of "fast food rage" at a South Shore restaurant in a week.

Another couple, upset over the slow delivery of their Kentucky Fried Chicken, assaulted a man at the fast food restaurant in Norwell last week, police said.

Witnesses said that couple yelled profanities at the restaurant employees when their food took too long, then beat up a man who asked them to stop for the sake of children in line.

Jared Garfagna, 31, and Sara Mohn, 24, both of Marshfield, are charged with assaulting the man as he left the restaurant.