A city government in eastern China says the death toll from an explosion at a chemical factory a week ago has jumped to 13.

A factory that produces adhesive materials exploded on Aug. 31 in Lijin county in Shandong province. The cause of the blast is under investigation.

Two days after the explosion, the official death toll stood at five. The Dongying city government, which administers the area, said the toll had risen to 13 following the completion of search and rescue efforts Saturday. It said 25 other people had been injured, 11 of whom were still hospitalized.

The blast came nearly three weeks after massive chemical warehouse explosions in Tianjin — about 300 kilometers (190 miles) away — exposed lax enforcement of safety regulations.