Sudan's ruling military council says it has foiled an attempted coup.
A spokesman, General Jamal Omar, announced on state television that more than a dozen people had been arrested – among them current and retired officers from the army and National Intelligence and Security Service.
"We saw the dangers and threats, which have been threatening the safety and security of this nation, by a group of people who refuse the demands of the people," Gen Omar said.
He added that the coup attempt was aimed at blocking a power-sharing deal being finalised between the military council and pro-democracy demonstrators.
It is not clear when that deal will be signed.
This is the third coup attempt that the country's military leaders say they have foiled, Sudan analyst Ahmed Kodouda told the BBC's Newsday programme.
"Many people are quite sceptical about the announcement but in reality there are significant centres of power that are interested in destabilising the transition," he added.