People celebrate "Monihei" Carnival in Cangyuan county, Yunnan province, on April 30, 2013. Ethnic Wa people throw and smear muddy water onto each other during the annual "Monihei" festival. Wa people consider the muddy water, which contains special plant juice, sacred and as a sign of good fortune. [Photo/Agencies]

Tourists visit the Tiananmen Square in Beijing, on April 30, 2013. Tourism boosted in Beijing during the three-day public holidays for the International Workers' Day which falls on May 1 every year. [Photo/Asianewsphoto]