Chants of "the people are stronger, stronger" and "retreat is not an option!" could be heard.

Officials said those being held also included industry minister Ibrahim al Sheikh, information minister Hamza Baloul, Mohammed al Fiky Suliman, a member of the ruling Sovereign Council, and Faisal Mohammed Saleh, a media adviser to Mr Hamdok.

Ayman Khalid, the governor of the state containing the capital, Khartoum, was also arrested, according to the official Facebook page of his office.

The arrests come after weeks of rising tensions between Sudan's civilian and military leaders, including a failed coup attempt in September.

Significant internet and mobile phone outages have also been reported.

NetBlocks, a group which monitors disruptions across the internet, said it had seen a "significant disruption" to both fixed-line and mobile internet connections across Sudan with multiple providers.

"Metrics corroborate user reports network disruptions appearing consistent with an internet shutdown," the advocacy group said.

"The disruption is likely to limit the free flow of information online and news coverage of incidents on the ground."

A military takeover would be a major setback for Sudan, which has struggled with a move to democracy since protests ended Omar al Bashir's long reign.

Josep Borrell, the EU foreign affairs chief, tweeted about his "utmost concern" over the situation, while US special envoy for the Horn of Africa Jeffrey Feltman said Washington was "deeply alarmed".