China has halted live poultry sales after more cases of people infected with the bird flu strain H7N9 increased.

The increase in cases comes at a bad time as more people are traveling in China ahead of the New Year, reports The Associated Press. Health officials noted their worry is around how some will travel in cramped conditions with live chickens nearby, which could further spread the flu.

Twenty people out of 96 reported cases have succumbed to bird flu. The deaths are primarily clustered around Eastern Shanghai.

The ban on live poultry sales is in effect for three weeks as officials begin culling whole populations of chickens to try and prevent the spread of disease. Already 20,000 birds are scheduled to be put down.

The bird flu news isn't good for KFC, according to Businessweek. Sales in China have suffered, but were starting to rebound ahead of the New Year, but the bird flu cases will easily dampen sales, which tend to increase during the Chinese New Year.

YUM Brans CFO Pat Grismer commented, "The Chinese New Year is a seasonally strong period for our business."

Sales last year also sagged after it became known that the company was using too much antibiotics because of the bird flu. Yum! Restaurants China CEO Sam Su noted that the flu "actually took a lot of people just completely out of poultry and didn't want to even think about it."