The 3.63 kilometres (2.26 mile), four-lane tunnel, which opened on Sunday, would cut the travel time from the city's eastern shore to the Hankou business district to seven minutes from the usual 30, the Shanghai Daily said, citing local authorities.

China, the world's fourth-largest economy, is spending heavily on infrastructure in a bid to ward off a hard landing for the economy, which is growing more slowly amid the global financial crisis.

China would open another two tunnels underneath the Yangtze in Nanjing, capital of eastern Jiangsu province, and in financial capital Shanghai, by 2010, the paper said.

China opened the world's longest cross-sea bridge in May, a 12 billion yuan project linking Shanghai with the port city of Ningbo. -- REUTERS