Islamabad - Conservationists have rescued a blind dolphin from the shallow waters of a canal in southern Pakistan, the Dawn newspaper reported on Friday.

The Indus Blind Dolphin, one of the world's most threatened mammal species, was saved on Thursday after a six-hour operation at Dadu Canal in the Sukkur district.

The three-year-old female dolphin had strayed into the canal from the Indus River, which has a documented population of just around 1,000 of the blind mammals.

Dawn said the 1,2-metre long dolphin weighing 20 kilograms was later released into the Indus River.

The rescue effort came days after the local wildlife department discovered two dead blind dolphins on the river banks.

Environmentalists say decreasing water levels and contamination by toxic industrial waste thrown into the Indus River has taken the threat to these dolphins to critical levels. (dpa)