Four civilians were killed and 14 others were injured in the Karrari district of Khartoum, a health ministry spokesperson said.

Sudan's army launched the attack, which involved artillery and air strikes, in its biggest operation to regain ground there since early in its 17-month war with a paramilitary group, the Rapid Support Forces (RSF).

The push by the army, which lost control of most of the capital at the start of the conflict, came ahead of an address by its commander General Abdel Fattah al-Burhan at the United Nations General Assembly in New York later in the day.

Separately senior military officers told Sky News that forces have crossed three key bridges: Halfaya bridge into Bahri, and Fiteihab and White Nile bridges into the central part of Sudan's capital.

However, Reuters news agency said the RSF had claimed to have prevented the army attempting to cross two bridges.

The RSF has continued to make advances in other parts of Sudan in recent months in a conflict that has caused a vast humanitarian crisis, displacing more than 10 million people and driving parts of the country to extreme hunger or famine.

Diplomatic efforts by the United States and other powers have faltered, with the army refusing to attend talks last month in Switzerland.

Hundreds dead in cholera outbreak

The number of people who have died in Sudan's cholera outbreak has risen by nearly 100, or almost 20%, in just two days, Sudan's health ministry has said.

A total of 473 people have died since the country's rainy season began two months ago. There have been nearly 15,000 cases across 10 states.

Cholera is a highly contagious disease which is transmitted through contaminated food or water. It causes diarrhoea and severe dehydration and can be fatal if not immediately treated.

A vaccination programme is currently under way.

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Artillery shelling and airstrikes

At least 78 civilians have been killed due to artillery shelling and airstrikes since the beginning of September in the Khartoum area, Jeremy Laurence, a spokesman for the UN human rights office in Geneva, told the Associated Press on Thursday.

"Our immediate concern is for the welfare of civilians, and the likelihood of further displacement and damage to civilian infrastructure," he said.

For months, some of the worst fighting has been in the city of al Fashir, the capital of the North Darfur state.

The UN and human rights groups say the RSF and allies have led ethnically targeted attacks in al Fashir - something denied by the RSF.

The UN human rights office said it had documented summary executions, sexual and gender-based violence and abductions of women and young men.

The army and the RSF previously shared power after staging a coup in 2021.

The war began when tensions between the RSF and the army, who had been jostling for position ahead of an internationally-backed transition to civilian rule, erupted into open conflict.

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On Thursday, the head of Sudan's military General Abdel Fattah al Burhan told the UN that the RSF should be considered "a terrorist group" and was "receiving the support of some states in the region".

"The path towards an end to this conflict is clear in our view. First and foremost, we need to put an end to the hostilities. The militias must withdraw from all of the areas they currently occupy.

"Second, this end to hostilities must be accompanied with a comprehensive political process."