(CNN)An emergency proclamation requiring face masks in stores and restaurants in Stillwater, Oklahoma, was nixed after store and restaurant owners received threats.

The proclamation was issued Thursday. Among other things, the order made businesses require patrons to cover their faces to combat the spread of coronavirus.

But on Friday, Mayor Will Joyce softened the rule to encourage, not require, face coverings, after several reports emerged of employees being verbally abused and being threatened with physical violence while trying to enforce the order -- all in just three hours of the rule going into effect.

"Many of those with objections cite the mistaken belief the requirement is unconstitutional, and under their theory, one cannot be forced to wear a mask. No law or court supports this view," said City Manager Norman McNickle in a statement. "It is further distressing that these people, while exercising their believed rights, put others at risk."