Hundreds of Ethiopians from the northern Tigray region have crossed into neighbouring Sudan over the past two days, fleeing fighting near the border, Sudanese security and medical sources told AFP.

The influx comes as Sudan itself remains engulfed in a brutal civil war between the army and the paramilitary Rapid Support Forces (RSF), which erupted in April 2023.

A member of the Tigray People's Liberation Front (TPLF) said clashes involving heavy artillery and drones between the Ethiopian army and Tigray rebels erupted in the western Tigray area of Shererina, near the Sudanese border, early on Saturday and continued until around 5:00 am (0200 GMT) on Sunday.

A Sudanese security source in the border town of Hamdayet said arrivals from Tigray included wounded rebels.

A medical source at a border health centre said the injured received first aid before being transferred to al-Hashaba, 15 kilometres (nine miles) inside Sudan, home to thousands displaced by the 2020-2022 Tigray war.

Residents on the Sudanese side of the border reported hearing explosions and sustained gunfire throughout the fighting.

A witness in Wad al-Hulaywah, about 40 kilometres from the frontier, said three powerful explosions were heard on Saturday morning.

"At around 4:30 pm local time, I could still hear heavy gunfire," the witness told AFP, adding that residents of nearby al-Qudaymah village had fled across the Setit River.

Another witness in Hamdayet said explosions were audible throughout Saturday and that he "saw aircraft flying south-west of Hamdayet".

On Saturday, the TPLF accused Ethiopia's federal government of launching what it described as a "large-scale infantry offensive", a claim the authorities did not immediately address.

Federal troops and Tigray rebels have massed along northern Tigray's border for months, fuelling fears of renewed conflict between the two sides less than four years after a war that killed at least 600,000 people, according to the African Union.