Four people are confirmed dead and several others injured in a Shanghai gas station explosion on Saturday, police and witnesses said.

One of the dead was a cyclist who was passing the gas station on South Yanggao Road in the booming Pudong New District when the blast went off at around 8:00 AM, said a policeman at the site.

He said identities of the other three dead are not immediately known, and an investigation has been launched.

Strong vibrations caused by the blast also affected a passing bus and injured several passengers on board, police said.

One witness, who gave only his surname as Quan, said he saw thick smokes but no flame from the site. "Several vehicles nearby were damaged," he said.

Photos posted at sina.com, a Chinese portal website, show window panes of nearby buildings have been broken.

The gas station, an outlet of China National Petroleum Corporation (CNPC), is said to be under renovation and will open later this month.

CNPC's Shanghai branch refused to comment.

(Xinhua News Agency November 24, 2007)