At least 16 civilians have reportedly been killed in an exchange of rocket fire between Sudan’s army and the paramilitary Rapid Support Forces (RSF) in the war-torn Darfur region, which has seen some of the worst violence since fighting began in mid-April.

On Saturday, a local lawyers’ union said it happened in the city of Nyala, the capital of the state of South Darfur.

The Darfur Bar Association said that the fighting led to the killing of 16 civilians, including an entire family, which lost all of its members with the exception of one, who sustained injuries.

There were also reports of snipers targeting people in West Darfur, including its capital of el-Geneina, near Chad, and tens of thousands of residents have fled across the border.

At least one man was killed by a sniper, the Darfur Bar Association added.

“Thousands of people continue to flee from the region of West Darfur and try to make it to the border into neighbouring Chad. That’s in West Darfur where we’ve seen a high increase in violence with refugees who arrived in Chad, saying that they’ve been targeted by militias allied with the RSF based on their ethnicities,” said Al Jazeera’s Hiba Morgan, reporting from Khartoum.

Fighting in the vast region, already ravaged by brutal conflict in the early 2000s, has intensified since mid-April when Sudan’s rival generals began vying for power.

The war, which broke out in the capital Khartoum on April 15 and spread to Darfur later that month, has left at least 3,000 dead across Sudan, according to a conservative estimate.

It has pitted army chief Abdel Fattah al-Burhan against his former deputy Mohamed Hamdan Daglo, commander of the paramilitary RSF.

“The Darfur Bar Association is also worried that the fighting will expand and include other parts of south Darfur. There has been fighting there before. Civilians have been caught in the crossfire but this time, the association said that even those refugees or displaced people who are in camps as a result of 20 years in Darfur may be targeted as violence continues,” Morgan said.

Fighting in Darfur, an RSF stronghold, has recently concentrated around Nyala, after brutal clashes in el-Geneina where the United Nations had reported atrocities.

Battles have also continued in and around Khartoum. Residents reported on Saturday the first army air raids on villages in the Gezira state’s north, just south of the capital.

The fertile land between the White Nile and Blue Nile rivers now hosts several hundred thousands of the estimated 3.3 million people the war has displaced.

If fighting expands into Gezira, they may be forced to flee again.

The humanitarian workers who support them would have to move as well, but fear the many bureaucratic challenges in relocating their operations.

Experts have said both warring sides would like to see the battlefield expand.

“The RSF has held the upper hand in Khartoum since the early days of the war, but that advantage is only growing more apparent,” the International Crisis Group (ICG) think tank said.

The army on July 15 launched a major offensive in North Khartoum, flattening entire suburban neighbourhoods with air raids, “but it failed spectacularly”, ICG said.

The RSF, meanwhile, is trying to seize the main Darfur-Khartoum road to ensure a constant supply of fighters and weapons.

Both Burhan and Daglo have representatives in Saudi Arabia, where truce talks have in theory been taking place.

But on Friday, the government in Khartoum denied “any information concerning a near truce”.