Image copyright AP Image caption The eagle is believed to be male, since a female was discovered in a nearby nest

Bird-rescue volunteers are trying to find a bald eagle photographed over the weekend in the US state of Pennsylvania with a leg-hold trap on its talons.

The bird was first spotted on Sunday afternoon struggling to fly with a long chain hanging from the clamp on its legs, but it has not been seen since.

Wildlife rehabilitator Wendy Ebersole Looker said the raptor's snared limb could become infected.

Experts say the bird will probably die if it is not found quickly.

Image copyright AP Image caption The trapped eagle struggled to fly under the weight of the clamp

Ms Looker said the weight of the clamp will stop the bird from flying high enough to safety.

She also said the object will hamper the eagle from using its talons to hunt, eat and perch.

Susan Boardman, who first spotted the bird and reported it to state game officials, said that "without intervention, this eagle will probably die".

She said it struggled to fly away as she took its photo.

"It was heartbreaking to see him like this," she said.

Image copyright AP Image caption Eagles, like these in British Columbia, use their talons for defence, eating, and perching

According to the state Game Commission, leg-hold traps must not be set out in the open, where the bait can attract birds of prey.

The traps must also be staked down, and labelled with the trapper's name.

They are commonly used on small game such as foxes, raccoons and bobcats.

Setting traps illegally could result in criminal charges, said Travis Lau, a spokesman for the Pennsylvania Game Commission.

Bald Eagles were placed on the endangered species list in 1978, but were removed once populations recovered, though it remains illegal to kill them.

On Tuesday a bald eagle in North Carolina was found shot in the head.