After the fireworks comes the clean-up. About 30,000 sanitation employees in China's finance hub worked through the night to sweep up some 1,200 tons of fireworks debris, left behind by revelers on Sunday evening as they welcomed in the Lunar New Year.

The seven-day holiday is the country's most important festival.

Fireworks are a longstanding tradition in China's Spring Festival, and they've made a loud return to Shanghai since it lifted a 12-year ban in 2006.