Premier Li Keqiang talks with Zhu Hongmei at the hospital. LIU ZHEN / CHINA NEWS SERVICE

More than 3,000 people are participating in the rescue. The Chinese People's Liberation Army navy sent more than180 divers to the site.

Near Erjitou, about 30 minutes by boat from the site, at least 70 members of a pontoon bridge troop from Wuhan, Hubei province, were waiting for orders.

The troops left Wuhan at around 7 am on Tuesday in a convoy of 20 trucks carrying assault boats, according to Su Junjie, a publicity officer of the unit.

By 6:30 pm, Su said, they were still waiting for their turn to offer help as other rescuers had been diving to search for survivors and were trying to turn the vessel upright.

The search and rescue operation had been made difficult by lingering rain throughout Tuesday.

Liu Yang, who lives near Erjitou, said heavy rain began to hit the area at around 7 pm on Monday. It peaked at around 9 pm, with thunder and lightning strong enough to smash windows and cause a power outage to much of his community.

"We have never seen such bad weather," the 35-year-old said. "And I have never heard of an accident more disastrous than the one last night."

The Guangdong Maritime Safety Administration has launched a safety inspection of passenger vessels, ferries and hazardous goods vessels across the province.

In the monthlong campaign, which started on Tuesday, workers in the sector will be trained on safety issues, review emergency programs, take emergency drills and eliminate flaws in safety management.

The administration will conduct a thorough check of the weather alert issuing system.

June marks the start of the tourism season in China and is part of the storm season featuring high temperatures and frequent rain storms.