Overdose deaths involving fentanyl increased sharply between 2019 and 2020, according to a new government report. The rise was greatest in Western states, according to the Centers for Disease Control and Prevention (CDC). More than 56% of people who died from fatal fentanyl overdoses had no pulse when first responders arrived on the scene, HealthDay reports.

Overall, most of the fatal overdoses involved injection drug use. In Western states, “evidence of snorting, smoking or ingestion, but not injection, was reported in 57.1% of deaths,” according to the report.

Last month, the CDC found that almost two-thirds of the more than 100,000 overdose deaths in the United States between May 2020 and April 2021 were tied to illicitly manufactured fentanyl or its chemical analogues.

The authors of the new report said fentanyl-related deaths seem to have accelerated during the COVID-19 pandemic. Only the Northeastern states have shown any signs of such deaths leveling off, they said.