The captain and the crew members were not on board the Indian oil tanker as it was handed over for repairs at a shipyard in Zhejiang province yesterday, said Indian officials from Shanghai, who were in touch with port authorities.
Seven Chinese workers, who were repairing the tanker at the Haizhou shipyard in Zhoushan city, were killed when it exploded and caught fire, according to local officials.
It was unloaded when the incident took place, they said, adding that the cause of the accident is under investigation.
There was no report of an oil spill.
A number of commercial ships, including many from India, are repaired in Zhoushan city harbour.