More than 10 million people have visited the Shanghai World Expo since its opening on May 1, the event's organizers said Saturday.

About 3.5 million of the total paying visitors traveled with package tour groups, the Bureau of Shanghai World Expo Coordination said in a press release.

On Saturday alone, 471,600 had toured the Expo Park by 2 p.m., it said.

The daily number of visitors has exceeded 300,000 since May 21. The biggest number was reported on May 29, when about 503,600 people toured the park.

On Thursday and Friday, the daily number of visitors exceeded 400,000.

Zhang Yunjie, an official in charge of operations at the Shanghai Expo Park, said more outdoor cooling devices and umbrellas were being installed as the middle of summer approached.

"We're also working to speed up security checks at entrances and ensure food safety in the park," Zhang said.

Large crowds of visitors, particularly students, are expected at the Expo during the school holidays in July and August. The Expo runs till Oct. 31.