Sudanese security forces fired tear gas canisters in the face of thousands of demonstrators, in the streets of the capital, Khartoum, who are calling for the army to withdraw from political life.
Earlier, it was reported that the Sudanese authorities had suspended some internet services.
And the Agence France-Presse news agency quoted the “NetBlocks” group to monitor the Internet as saying that Internet services via mobile phones were cut off in the morning, coinciding with the start of the gathering of demonstrators in several cities and towns.
Archyde.com witnesses also reported that internet services in the capital, Khartoum, appeared to be down before the protests.
The authorities also set up roadblocks on several roads in Khartoum.
This is the first demonstration this year and the twelfth since the army, led by Lieutenant-General Abdel Fattah Al-Burhan, overthrew the civilian government, headed by Abdullah Hamdok, last October.
Hamdok was reinstated a month later, but the demonstrations continued.
More than 50 people have been killed since the protests began.