Heavy artillery fire in a market in the Sudanese capital, Khartoum, resulted in at least 17 deaths and 106 wounded.
The attack took place on Wednesday according to a statement issued by the Sudanese Doctors' Syndicate on the day.
A ceasefire previously signed by the Sudanese government forces and the rival Rapid Support Forces was extended on Monday but the fighting continued.
Both sides accuse each other of violating the ceasefire agreement repeatedly.
On Wednesday, the Sudanese Armed Forces announced that it had suspended dialogue with the Rapid Support Forces.
On Thursday, the US announced sanctions against the Sudanese army and the RSF.