The National Green Tribunal (NGT) said the 500km (310-mile) stretch between Haridwar in Uttarakhand state and Unnao in Uttar Pradesh needed urgent action.

The court also ordered that anybody who dumps waste in the river could be fined up to 50,000 rupees (£600; $775).

The NGT's orders are legally binding but can be challenged in the courts.

The environment court ordered the Uttar Pradesh government to move hundreds of tanneries away from the river in Kanpur. It set a deadline for its demands of six weeks.

The tanneries are a major source of employment for many Muslims in the area, but they heavily pollute the river.

The NGT is known for passing strict orders to protect the environment, but its rulings are often challenged in high courts and the Supreme Court.

The court also does not have an agency to enforce its orders, and it relies on state law enforcement.

The Uttar Pradesh government is yet to make a statement on the NGT's latest ban on waste dumping by the Ganges.

The river is sacred to Hindus who worship it as "Mother Ganges", but it has also become badly polluted by industrial waste, sewage and dead bodies, apparently dumped by families who could not afford cremations.

Prime Minister Narendra Modi has promised several billion dollars for a massive clean-up of the river.

But activists say the pace of the operation to clean the river has been slow.