By Leonardo Benassatto and Ana Mano

SAO PAULO (Reuters) -At least eight people have died, one was missing and nearly a dozen others wounded after a grain silo explosion on Wednesday at an agricultural co-operative in southern Brazil, the government of Parana state said on Thursday.

The blast occurred at the C.Vale co-operative in the small town of Palotina, about 600 km (370 miles) from the state's capital Curitiba. Parana is one of Brazil's top farm states.

C.Vale did not immediately respond to questions about the circumstances of the incident.

C.Vale, which stores grains in 125 units across five Brazilian states and in Paraguay, said in a statement that rescue workers were still scouring the rubble in search of the missing person on Thursday.

It said nearly a dozen people had been hospitalized, excluding the fatalities.

Jose Ricken, president of Parana's farm cooperative group OCEPAR, told reporters this was an isolated case, adding the explosion was fatal and that no similar incident had occurred in the area "in a long time."

Ricken declined to speculate on the causes of the explosion, deferring questions to authorities as investigations are still ongoing.

Experts say grain dust particles are highly combustible and can cause fires or explosions in confined spaces such as grain storage facilities.

The particles can be from wheat, oats, barley, or other types of grain that form layers or become airborne in an enclosed space. Research shows corn starch is one of the most dangerous and volatile.

Fire Department Official Manoel Vasco said dogs were helping in the search of the missing worker potentially trapped under a pile of grains.

Agriculture Minister Carlos Favaro and President Luiz Inacio Lula da Silva both wrote on messaging platform X, formerly known as Twitter, saying they received the news of the explosion and deaths with sadness.

Acting Parana Governor Darci Piana headed to Palotina, a city of some 35,000 people, alongside state secretaries to follow the rescue operations and provide support to the families, the government said.

(Reporting by Leonardo Benassatto and Ana Mano; Writing by Gabriel Araujo; Editing by Christina Fincher, Bernadette Baum and Alison Williams)