KITCHENER -- Police are investigating an alleged assault at Tim Horton's restaurant in Waterloo, Ont.

They say a male customer attempted to order drive-thru at the Westhill Drive location around 9:40 a.m.

After being denied service, he became upset.

Waterloo Regional Police say the customer then attempted to spit on at least one staff member before leaving the property.

The male is described as approximately 5'10, clean-shaven, and with short black hair. He was last seen wearing all black, including a baseball cap, sweater, pants and shoes.

Police have also released an security image of the suspect.

This is the second spitting incident reported in southwestern Ontario in the last week.

On April1 a man allegedly struck and spit on a female clerk at a Guelph grocery store. His photo was also released to the public and led to an arrest days later. A 21-year-old man from St. Thomas, Ont. has been charged with assault.

Also on Tuesday, a man in Stratford allegedly coughed on a LCBO employee and was heard telling other people in line that it wasn't "worth the wait just to cough on the cashier."