A statement from the committee for pro-democracy lawyers said the shells hit the market in Omdurman during an intense exchange of fire between the two sides.
“More than 20 civilians have been killed and others have been wounded,” said the statement, which was sent to AFP. The committee keeps track of rights violations during the conflict and its civilian victims.
On Saturday, a medical source said shells that hit houses in Khartoum had killed 15 civilians.
Omdurman has repeatedly been the site of fierce battles between the two sides.
Though most of the fighting was previously contained to the capital and the western region of Darfur, it has also spread to areas south of Khartoum according to witnesses.
More than 10,000 people have been killed in the Sudan conflict so far, according to a conservative estimate by the Armed Conflict Location & Event Data project.
But aid groups and medics have repeatedly warned the real toll exceeds recorded figures, with many of those wounded and killed never reaching hospitals or morgues.
The war has caused an estimated 5.5 million people to flee, both within Sudan and across borders, according to the United Nations.
AMK/PR
