Concerns are growing in southern California over a cluster of “exceptionally rare” cancer cases that has sickened multiple children in a suburban community.

Families living in the Orange county neighborhood of Ladera Ranch, home to about 26,000 people, have reported that six children in the community were diagnosed with Ewing sarcoma, Katrina Foley, the vice-chair of the county board of supervisors, said in a statement.

Ewing sarcoma is a rare cancer that primarily affects bone and soft tissue and is largely seen in young adults and children.

At a community meeting this week, hundreds of residents turned up to voice their concerns, including several who spoke about additional cancer cases in adults and pets. While the American Cancer Society reports there are “no known lifestyle-related or environmental causes” of Ewing sarcoma, many residents believe the cancer cases are linked to the use of herbicides and pesticides.

“We’re very concerned about pesticides that are being sprayed all around the community,” Liesl Heizt told ABC7. “There’s so many times that I walk around and they’re spraying, and I ask what they’re spraying and they’re not telling us.”

During the meeting, Brian Dalton spoke about his daughter Lily who died earlier this year after being diagnosed with a rare cancer linked to a genetic abnormality seen in the other cases, KTLA 5 reported.

“I don’t want another mother holding her child’s hand through endless treatments, praying for one more birthday, planning a funeral instead of a future,” Dalton said.

In a letter sent last week, Foley urged the state to expedite a review of the cases and give residents “timely, transparent updates”.

“Ladera Ranch families deserve answers, transparency and urgency from the state,” Foley said. “We do not yet know what caused these cancers, but that uncertainty demands a comprehensive review of every credible factor, including possible environmental exposures, along with direct communication and the public release of the findings.”

Last week, Bill Essayli, an assistant US attorney, asked the Environmental Protection Agency to investigate the cluster to determine if there is an environmental cause behind the cases. At least six children have been diagnosed with the rare bone and soft-tissue cancer, he wrote.

“The Centers for Disease Control and Prevention (CDC) and National Cancer Institute recognize that unusual patterns of cancer and community concerns regarding potential environmental exposures should be evaluated through a systematic, science-based process,” Essayli said.