Mexico City, Mexico - About 300 professional clowns from Mexico and Central American gathered in Mexico City last week for a four-day convention to trade jokes and hone skills like making balloon figures.

They gathered Wednesday at Mexico City's Mother's Monument under the slogan "Clowns For Peace, A World Without Violence."

Posing for a group picture the clowns then set about laughing, tee-heeing and guffawing for about 15 minutes, on the premise that a world with more laughter will have less time or appetite for violence.

They say they hope their 15-minute non-stop laugh-a-thon will make a contribution to world peace.