Two dogs have been seized by police after 32 sheep were killed and more injured at wildlife reserve RSPB Saltholme over the last two weeks.
Cleveland Police says the locally owned German Shepherd dogs were seized after the latest incident on Monday when 11 sheep were killed and 38 others injured.
In total, 32 sheep have been killed at the reserve near Billingham over the last two weeks. A large number of those were expecting lambs.
Enquiries are continuing into the circumstances surrounding the incidents and anyone with information is asked to contact PC Lisa Kennerley on the non-emergency number 101 or Crimestoppers anonymously on 0800 555 111 or www.crimestoppers-uk.org.