"Sophisticated Chinese weaponry, re-exported by the United Arab Emirates, has been captured in Khartoum, as well as used in Darfur in a blatant breach of the existing UN arms embargo," Amnesty said in a statement.

The rights group said it identified "Chinese GB50A guided bombs and 155mm AH-4 howitzers" through analysis of video footage and photos of attacks by the paramilitary Rapid Support Forces (RSF) in the capital Khartoum and Darfur.

Since April 2023, the RSF has been at war with Sudan's regular army, in a conflict that has killed tens of thousands, displaced 13 million and created the world's largest displacement and hunger crises.

"This is clear evidence that sophisticated Chinese-made guided bombs and howitzers have been used in Sudan," said Brian Castner, head of crisis research at Amnesty.

Drone strikes attributed to the RSF have increased in recent days, targeting strategic sites in the army-held seat of government in Port Sudan on the Red Sea.

Sudan's government on Tuesday severed diplomatic ties with the UAE, accusing it of supplying the RSF with strategic and advanced weapons.

The weapons identified "are manufactured by the Norinco Group, also known as China North Industries Group Corporation Limited, a Chinese state-owned defence corporation", according to Amnesty.

It said "the only country in the world that has imported AH-4 howitzers from China is the UAE" in a 2019 deal, relying on data from the Stockholm International Peace Research Institute.

Abu Dhabi has repeatedly denied arming the RSF, despite reports from UN experts, US politicians and international organisations.

The London-based watchdog said "this is the first time GB50A bombs have been documented in active use in any conflict worldwide," and were "almost certainly re-exported to Sudan by the UAE".

"It is shameful that the UN Security Council is failing to implement the existing arms embargo on Darfur, and not heeding calls to extend it to all of Sudan," Castner said.

Last year, Amnesty International documented that manufactured weapons from countries including China, Russia, Turkey and the UAE had been transferred into and around Sudan.

It also revealed that French-manufactured weapons systems were being used on the battlefield in the conflict-torn country.

The war, now in its third year, has pitted the armed forces led by General Abdel Fattah al-Burhan against the RSF headed by his former deputy Mohamed Hamdan Daglo.

It has effectively split the country in two with the army controlling the north, east and centre and the RSF dominating nearly all of Darfur and parts of the south.