YEOSU -- Police raided the head office of a Seoul-based major chemical company and its plant in this provincial city on Monday as part of efforts to determine the exact cause of an explosion last week that killed six workers and wounded 11 others.
All of the victims are contract workers who were doing welding work on a storage tank at Daelim Industrial's plant in Yeosu, a port city on the nation's southern coast.
The exact cause of the March 14 blast has yet to be determined, with surviving workers claiming that the tank, which stored high-density polyethylene, was not fully cleaned before the welding work was to be done, a claim denied by the company.
On Monday, police in South Jeolla Province where Daelim's plant is located, raided the company's head office in Seoul and its plant in this provincial city to secure evidence that may shed light on the cause of the accident.
Also raided was the company's lab in the central city of Daejeon where police sought to seize relevant documents about jobs at the factory, including the history of maintenance activities at the plant.
"The raid is part of our investigation into the exact cause of the accident and if there are any lapses by the company officials over the course of the operation," said an officer.
"We are analyzing video materials from closed-circuit televisions around the factory, and waiting for the forensic analysis due later this month," the officer added.
Meanwhile, the bereaved families agreed with the management to hold a funeral for the victims on Tuesday. The funeral has been delayed due to confrontations between the two sides over who should be held responsible for the accident and the extent of compensation for the victims.