Twenty rare birds have been found dead and another 13 poisoned after being tainted by a highly-toxic pesticide in northern Tianjin city's wetlands in China.
The birds that have been poisoned are not in life-threatening condition, state-run Xinhua news agency quoted local police as saying.
The birds, Oriental white storks, stopped at the city's Beidagang Wetland Nature Reserve along their migratory route when they were poisoned by the wetland water.
The water was confirmed to have contained carbofuran, also known as furadan, one of the most toxic carbamate pesticides.
The remains of the dead and the poisoned birds were discovered after an amateur photographer found the dead body of a stork on November 11, while other kinds of birds have also been found dead.
Local authorities are diluting the tainted water and looking for the sources of the pesticide.
The Oriental white stork is listed under China's highest level of animal protection, as only 2,500 to 3,000 of them currently exist in the country.
The species, which usually reproduces in the northeast, migrate south for winter, and the Beidagang Wetland is an important habitat along their migratory route.