The powerful storm pounded heavily populated Guangdong province with gale force winds and torrential rains, touching down in Gangkou town around 7:50 pm (1150 GMT) Tuesday, the Xinhua news agency said.

It swept through several cities in Guangdong, including the capital Guangzhou as well as the economic boom town Shenzhen, and the cities of Shantou and Shanwei, destroying thousands of houses.

Local officials said Wednesday they were still struggling to determine the extent of the damage, but information gathered so far reveals an extensive impact.

In Shenzhen, the hardest-hit city, 20 people were killed, including 16 migrant workers who were building a factory on a construction site where several buildings collapsed, according to the Shenzhenn-ews.com website and the Xinhua news agency website.

Twenty other workers on the site were injured.

Altogether, a total of 98 people were injured in Shenzhen, 20 seriously injured and 78 slightly, said the websites, adding that two others were missing.

The typhoon was the worst to hit Shenzhen since 1979, the Shenzhen website said.

Some 4,000 people had to be evacuated from unsafe homes, prompting the civil affairs department to open 272 emergency shelters, which housed nearly 5,000 people including evacuees and those whose homes collapsed, the website said.

More than 6,000 trees were uprooted and many electricity poles were knocked down, causing two districts in Shenzhen to suffer power outages.

Seventy flights in the city were cancelled.

In other parts of Guangdong province, seven more people were killed and another 18 injured.