NEW YORK, July 25 (UPI) -- At least 1,000 people died in a two-year surge of fatalities resulting from an illegal version of the painkiller fentanyl, government officials said.

The federal Centers for Disease Control and Prevention disclosed the number of deaths in the first government review of the death surge's impact, The Wall Street Journal reported Friday.

Fentanyl is frequently given to patients with cancer or other conditions causing serious pain. The drug can be used to make a narcotic powder that is significantly stronger than than heroin, said T. Stephen Jones, a consultant and former CDC official wrote the report.

A flood of deadly overdoses took place in a number of metropolitan areas across the United States from 2005 to 2007, the agency's report indicates.

The report says the drug's production was eventually suppressed by a legal crackdown.

The surge of overdoses marked the only time illegally made fentanyl was blamed for a significant jump in U.S. deaths, the newspaper said.