Nanjing - A trio of explosions at chemical plants and an oil tanker in eastern China Friday killed at least 12 people, rescuers said.

The blast, which broke out at 8:45 a.m. on Friday at the Fuyuan Chemical Plant, a producer of Dichloro Fluoro Benzene for industry in Jiangsu Province's Linhai County, also left more than 10 people injured who had been sent to a local hospital.

More than 7,000 people have been evacuated within two km around the company, rescuers said.

Nearly 1,000 rescuers are searching for the possible missing people in the debris and the death toll may increase, according to the rescuers.

One hour before that blast, an explosion and fire ripped through a plant belonging to the Shanghai Yuanda Peroxide Co. Ltd., seriously injuring at least four people and throwing up thick smoke across the city's Baoshan industrial district to the city's north.

The fire was quickly brought under control and investigators were looking into the cause, said a woman who answered the phone at Yuanda's headquarters in Shanghai.

The Yuanda explosion had initially been ruled an industrial accident with no sign of foul play.

Yuanda's Web site describes it as a joint venture with a Hong Kong company that produces 50,000 tons per year of the chemical peroxide.

Shortly before the Yuanda accident, a massive explosion split the hull of an oil tanker sailing down a canal in central Jiangsu's Yizheng district.

Two people aboard the boat were reported missing after the blast and feared dead, the report said. Another person was taken to a hospital in critical condition.

The company is a major producer of fluorochemicals for industry. The blast's influence on environment of nearby areas is being monitored and cause of the accident is under investigation.