(NewsNation) — Authorities have confirmed bones were found during the search for Travis Decker, according to local media reports.

Authorities have been on the lookout for Decker, who faces charges for the murder of his three daughters — 9-year-old Piatyn, 8-year-old Evelyn, and 5-year-old Olivia — during a scheduled visit.

The FBI announced Thursday it had completed a two-day search of the Washington state campground where the girls’ bodies were found.

Bones were among the items recovered, Chelan County Sheriff Mike Morrison told local media.

He said the bones were not a complete skeleton, and it was not clear if they were human or animal bones.

The bones were sent to Central Washington University’s anthropology department to be tested to determine their origin.

The remains of Decker’s three daughters were discovered at the beginning of June beside his vehicle near the Rock Island Campground close to Leavenworth, after he failed to return the children to their mother’s residence in Wenatchee.

Decker was not found, prompting a widespread search throughout Washington. Nonetheless, by late July, the Chelan County Sheriff’s Office reduced its efforts due to fewer new leads in the investigation.

In late June, the authorities considered the possibility that Decker may have also died while escaping law enforcement. They also warned that he might have altered his appearance during the weeks following to evade capture.

The U.S. Marshals Service is offering a reward of $20,000 for any information leading to Decker’s arrest.

“This case has deeply unsettled our nation,” Chelan officials reported in a statement. “The untimely loss of Paityn, Evelyn, and Olivia Decker was the result of a shocking and senseless act of violence. We continue to hold their loved ones in our thoughts and are steadfast in our pursuit of justice on their behalf.”

Officials are encouraging anyone who sees Decker to call 911 immediately and not to approach him, as he is considered armed and dangerous.

The Associated Press contributed to this report.