KHARTOUM: Sudanese authorities said they had foiled an attempted coup on Tuesday, accusing plotters loyal to ousted president Omar al-Bashir of a failed bid to derail the revolution that removed him from power in 2019 and ushered in a transition to democracy.

Sudan's military said 21 officers and a number of soldiers had been detained in connection to the coup attempt, and a search continued for others involved. All locations affected by the attempt were under army control, it said.

The coup attempt points to the difficult path facing a government that has reoriented Sudan since 2019, winning Western debt relief and taking steps to normalise ties with Israel, while battling a severe economic crisis and facing down challenges from those still loyal to Bashir.

A ruling body known as the Sovereign Council has run Sudan under a fragile power-sharing deal between the military and civilians since the overthrow of Bashir, an Islamist shunned by the West who presided over Sudan for nearly three decades.

Elections are expected in 2024.

"What happened is an orchestrated coup by factions inside and outside the armed forces and this is an extension of the attempts by remnants since the fall of the former regime to abort the civilian democratic transition," Prime Minister Abdalla Hamdok said in a televised statement.

"This attempt was preceded by extensive preparations represented by lawlessness in the cities and the exploitation of the situation in the east of the country, attempts to close national roads and ports and block oil production."

The streets of the capital Khartoum appeared calm, with people moving around as usual and no unusual deployments of security forces, a witness said.

Early on Tuesday morning, a witness said military units loyal to the council had used tanks to close a bridge connecting Khartoum with Omdurman, just across the River Nile.