PITTSBURGH (AP) _ A federal grand jury indicted a chemist and six other people in the distribution of the synthetic narcotic China White, which has been blamed for 13 deaths in the Pittsburgh area.

Thomas L. Schaefers, 48, of suburban Aspinwall was charged in the 33-count indictment handed up Monday of manufacturing 3-methylfentanyl in his basement and distributing it to two men who died of overdoses in May and July.

Schaefers is accused of producing the drug in several batches from late 1987 to September or October of this year. After police raided his house Dec. 1, they determined that about six ounces of the drug, which is similar to heroin, had reached the street, mostly in October and November.

Police believe as much as an additional 24 ounces of China White from the batches - enough for thousands of individual doses - remains unaccounted for.

Schaefers, who was arrested when his house was raided, is being held on bond. The other six were indicted on distribution charges.

Federal narcotics law provides a mandatory minimum 20-year prison term and a maximum of life in prison for those convicted of producing or distributing a controlled substance that causes a death.