Two more seals with plastic rings embedded in their necks, as well as two others tangled in netting, have been found on a Norfolk beach.
David Vyse, from the Friends of Horsey Seals wildlife group, said the four sightings were reported over the last couple of weeks in the Horsey area.
Volunteers from the group have managed to rescue three seals from the same area, but only after they were weakened enough to be caught.
A seal called Mrs Frisbee was saved in 2017 and released back into the wild the following year, and two other seals, called Pinkafo and Sir David, have also been nursed back to health in recent months.
The latest four injured animals remain in the wild, according to the group.
The sightings come as the RSPCA reported the number of animals affected by plastic litter is at an all-time high.
The charity says the number of incidents across the country has risen from 473 in 2015 to 579 in 2018.
To try to combat the problem, the Friends of Horsey Seals group have been handing out leaflets to urge people to not take flying rings to the beach.