The U.S. Food and Drug Administration (FDA) has provided an update on its investigation into an E. coli outbreak that it has been linked to romaine lettuce. The outbreak is thought to stem from romaine lettuce that was produced at farms in the Salinas, California, growing region.

The FDA is also investigating an E. coli outbreak from Fresh Express Sunflower Crisp Chopped Salad Kits that has sickened eight people in three U.S. states and 24 people in six Canadian provinces. This is in addition to a third E. coli outbreak from romaine lettuce at a restaurant chain in Washington state that has sickened at least 10 people.

The FDA is continuing its investigation into the three E. coli outbreaks and has not drawn “definitive conclusions” at this time. However, the agency, along with the Centers for Disease Control & Prevention, has identified a common grower of romaine lettuce between the three outbreaks.

More information will be provided to the public as it becomes available through its investigation, the FDA said.

To help contain the E. coli outbreaks, the FDA said it is working with producers, distributors, retailers, and foodservice companies to remove romaine lettuce from the market until it can determine the exact source for the contamination. The agency said it will continue to monitor romaine lettuce through 2020.

“As an agency, we remain laser-focused on prevention,” the FDA said. “Food safety is not a competitive issue, so everyone involved in the farm to table supply chain of fresh leafy greens (growers, distributors, retailers and foodservice companies) must work collaboratively, with a sense of urgency, and do everything possible to fully understand how and why these outbreaks continue to occur. Moreover, they must aggressively implement additional preventive measures to address any shortcomings identified to further protect consumers.