NANJING, May 30 -- A chemical plant blast in east China's Jiangsu Province has left one person dead, three injured and two others trapped as of Friday morning, local authorities said.

The blast occurred around 6:10 p.m. Thursday at Shuguang Auxiliaries Plant in Baoying County, sources with the county's publicity department said.

Witnesses said the blast was huge and could be felt within two kilometers.

As of 8 a.m., the trapped workers had not been retrieved, the sources said.

The injured, including one in serious condition, have been sent to a local hospital.

Rescue efforts and investigation into the cause of the blast are under way.