SHANGHAI: A senior Chinese official stressed that security would play the most important role in a successful Shanghai World Expo in 2010, during an investigation tour of Shanghai that ended Monday.

Zhou Yongkang, member of the Standing Committee of the Political Bureau of the Communist Party of China (CPC) Central Committee, watched an offshore anti-terrorism exercise Sunday.

More than 1,000 servicemen from across the country, using 29 ships and two helicopters, took part in the exercise, including hostage rescue, fire fighting and assaults on terrorists from the sea and the air.

When inspecting the World Expo site, Zhou, who is also head of the CPC Central Political and Legislative Affairs Committee, said that Shanghai should learn from the experience last year of the Beijing Olympics.

He said that the security of the Expo and Shanghai should come first in the nation during the World Expo and that risks of social unrest should be dealt with at the local government level.