Two bodies and a white powder, later determined to contain fentanyl, were discovered in a “human-dug cave” in Los Angeles, California, on Sunday, authorities said.

A Los Angeles Fire Department (LAFD) hazmat team was deployed to the neighborhood of Northridge, where two deceased men were found around 10:30 a.m. in a suspected homeless encampment, ABC7 reported.

The LAFD said the bodies were located “inside of a human-dug cave/excavation.”

An aerial view of the excavation from CBS News Los Angeles shows the opening and top of the makeshift structure, which appears to extend underground.

Due to the mysterious white powder found at the scene, hazmat-suited responders assisted in removing the bodies.

Officials later confirmed the substance contained “portions of fentanyl,” LAFD Battalion Chief Scott Hilton said.

“We were able to mitigate that, secure it. We will be disposing of that,” he added.

The two deaths are believed to be drug-related, but the medical examiner will officially determine the causes of the deaths. 

“Wind helped to dissipate the powder, and the hazmat team did not detect any hazardous readings at the scene,” the local outlet noted.