Nine people died Tuesday after an accidental blast at an explosives factory in southern Brazil, authorities said.

Axar.az, informs, citing France 24, six men and three women were unaccounted for following the blast.

"There is no longer any hope of finding survivors among the nine people who were at that location," Colonel Hudson, secretary of public security in Parana, told reporters.

Security forces assisted by dogs worked to search for the missing people. Seven others were injured and being treated at nearby hospitals.

"The area of the explosion was badly destroyed," fire department spokeswoman Luisiana Guimaraes said.

"Within a radius of approximately 1.5 kilometres, we have houses that were hit, with broken windows, damaged structures, and a huge shock wave."

Executives from Enaex Brasil, the company that owns the plant, said at a news conference the cause of the accident was being investigated.

According to authorities, residents of several nearby towns heard the explosion.