One of the bald eagles found dead recently in a farm field on Maryland’s Eastern Shore. (Maryland Natural Resources Police)

Authorities said they’ve found another dead eagle in Delaware, bringing the number of dead birds found there to five.

The fifth dead eagle was found Sunday about a mile away from where four others were found the day before near Dagsboro, Del.

Several eagles were also found alive but disoriented in a farm field in Sussex County, Del. Some of the eagles were being cared for by a rescue group in that area, but a few flew away before they could be captured.

It is not immediately known what killed the eagles or may have affected the others. Delaware Natural Resources police along with the U.S. Fish and Wildlife Service are investigating.

Catherine Hibbard, a spokeswoman for the U.S. Fish and Wildlife Service, said in a statement Tuesday that a law enforcement officer was on the scene in Delaware to collect evidence. That evidence, she said, would be sent for testing to a federal forensics lab in Oregon. Officials hoped to have preliminary results in the next few days as to the cause of death.

The deaths come after 13 bald eagles were found dead last month near a farm on Maryland’s Eastern Shore. That case is also under investigation by the federal wildlife service and under review at its Oregon lab. It is believed those eagles found in Federalsburg, Md., may have been poisoned. A $30,000 reward is being offered for information leading to a conviction.

Dagsboro, Del., is roughly 30 miles southeast of Federalsburg. Federal wildlife officials have said they do not believe the two cases of bald eagles are related at this point, but they noted that it could “change based on the investigation,” Hibbard said.

Martin Weil contributed to this report.