Dozens of families were Saturday fleeing violence in Sudan's Blue Nile State, where ongoing clashes between two tribes have killed at least 33 people, authorities said Saturday.

At least 108 others have been wounded, according to a health ministry statement, and 16 shops torched since the violence broke out on Monday over a land dispute between the Berti and Hawsa tribes.

"We need more troops to control the situation," local official Adel Agar from the city of Al-Roseires told AFP on Saturday.

According to him, many people were seeking refuge in police stations and the unrest had resulted in many "dead and wounded".

Agar did not give a toll breakdown but said mediators were urgently needed to de-escalate the violence.

Soldiers were deployed to contain the unrest and a night curfew has been imposed by the authorities starting Saturday.

Blue Nile governor Ahmed al-Omda issued an order Friday prohibiting any gatherings or marches for one month.

The violence broke out after the Berti tribe rejected a Hawsa request to create a "civil authority to supervise access to land", a prominent Hawsa member told AFP on condition of anonymity.

But a senior member of the Bertis said the tribe was responding to a "violation" of its lands by the Hawsas.

- Casualty numbers 'rising' -

Clashes resumed on Saturday after a brief lull, close to the state capital Al-Damazin, witnesses said.

"We heard gun shots... and saw smoke rising," resident Fatima Hamad  told AFP Saturday from Al-Roseires, across the river from Al-Damazin.

Ahmed Youssef, a resident of the state capital, said "dozens of families" crossed the bridge into the city to flee the unrest.

Hospitals put out urgent calls for blood donations, according to medical sources.

One source at Al-Roseires Hospital told AFP the facility had "run out of first aid equipment" and that reinforcements were needed as the number of injured people was "rising".

The UN special representative to Sudan, Volker Perthes, called on all sides to exercise restraint.

The "inter-communal violence and the loss of life in Sudan's Blue Nile region is saddening and deeply concerning," he tweeted.

By late afternoon Saturday "the situation had improved" in the Qissan region, according to Omda, the governor of the Blue Nile State.

But clashes continued in Al-Roseires, he said in televised remarks.

The Qissan region and Blue Nile state more generally have long seen unrest, with southern guerrillas a thorn in the side of Sudan's former strongman president Omar al-Bashir, who was ousted by the army in 2019 following street pressure.

Experts say last year's coup, led by army chief Abdel Fattah al-Burhan, created a security vacuum that has fostered a resurgence in tribal violence, in a country where deadly clashes regularly erupt over land, livestock, access to water and grazing.