Mexico City - Laughter was a serious matter at the 21st International Clown Convention, which brought professional clowns together in Mexico City this week for four days of workshops, classes and, well, just clowning around.

The traditionally festive meeting, which opened on Monday and ended Thursday, was not quite as cheerful this time around following the recent rash of creepy clown sightings that have sparked fear and hysteria in the U.S., Canada, Europe, and lately, in Mexico.

According to the Latin-American clown association, there are some ten-thousand professional clowns registered in Mexico, many of whom were not pleased at the prospect of their profession being stigmatized to the extent that it could affect their livelihoods.

"I don't see anything funny about it," said Emanuel Emiliano Fernandez, who performs in Argentina under the name 'Fluorescent Plug.' "Clowns make people laugh and happy."

This year's convention attracted 450 of professional clowns from 14 countries. Seminars included best practices for things like twisting balloons into shapes of animals. Attendees also competed in make-up applying contests and marched merrily through the streets.

Chanting "we are clowns, we are not murderers," they juggled, rode unicycles and handed balloons out to the delighted spectators as they paraded along the way.

Despite the shadow hanging over this year's event, the international community of clowns made good use of their time in Mexico City, honing the tricks of their trade, making people laugh and spreading around a lot of joy in hopes that a world with more laughter will have less time for violence.