As the Labor Day holiday on May 1 draws near, people who have booked tour packages to the Yangtze River Delta regions are becoming uneasy about an outbreak of H7N9 bird flu.

To date, no travel warning has been issued, but the daily update of H7N9 cases in the delta regions made a number of tour planners back down, which may hurt confidence in tourism in East China, especially Shanghai, where the first human case was reported and the flu is most serious.

By 4 pm Sunday, Shanghai had reported 24 H7N9 cases, nine of them fatal. Among the people infected was the husband of an H7N9 patient who had died. Health officials said there was insufficient evidence to determine that the man had caught the disease from his wife.

"I have already booked a tour for 1,500 yuan ($242) for the Labor Day holiday. The tour package covered Shanghai, Suzhou and Hangzhou. But the news said that the flu in that place was serious, so I became worried," said Zhang Yajun, 25, of Shijiazhuang, Hebei province.

"Because I worried the food might not be safe there, I decided to go to other places," Zhang said, adding she won't visit Shanghai this year.

Liu Yue, who works in Shanghai, also canceled a tour package. She had arranged for her parents to come for a few days to Shanghai from Sichuan province and then visit the West Lake, a tourist destination in Hangzhou, Zhejiang province.

"I got very concerned about my parents' health after I heard that most of the people infected are elderly. So I decided to cancel the tour," she said.

"There was a loss of money, but I think safety is more important."