Sudanese anti-aircraft crews shot down an "aerial target" near Khartoum's twin city of Omdurman, a military spokesman said on Wednesday, after witnesses reported hearing explosions in the area.

An air base detected the target around 10:45 pm (1945 GMT) on Tuesday flying at low altitude over Omdurman's Wadi Sayidna military area, checked there were no civilian planes nearby and shot it down, military spokesman Colonel Al-Sawarmy Khaled Saad said in a statement.

After it was hit, it disintegrated and its debris fell to earth in several residential areas of Omdurman, Saad said.

Saad described the downed aircraft as a "photographic surveillance target," but said it was still unknown where it came from and did not specify if it was a drone.

No one was hurt in the incident according to the statement, which was published on the website of the defence ministry.

Investigations were ongoing, Saad said, stressing the "stability of the situation" in the capital on Wednesday.

In an earlier statement, Saad had denied rumours of "an attempted coup, military clashes or a foreign attack" that circulated on Sudanese social media after the incident.

Witnesses in Omdurman said they heard loud explosions from outside the city late on Tuesday. The area is home to several military installations.

A resident of the city's Wad al-Bakhit neighbourhood told AFP they had heard several loud blasts.

"When we heard the noise from the explosion, the walls of our house shook and the blast was repeated four times," he said on condition of anonymity.

Khartoum has accused Israel of launching strikes on targets in Sudan several times in recent years, although Israel refuses to comment on the claims.