Heavy gunfire has been heard outside the army headquarters in the Sudanese capital Khartoum where thousands of protesters have been holding a sit-in for the third night in a row.
They are calling for the resignation of President Omar al-Bashir.
Witnesses reported seeing people running for cover after the shooting began. Earlier, tear-gas was fired.
It appears to be the latest attempt by government security agents to break up the protests.
One of the protesters, Ahmed Mahmoud, told the BBC that “tear-gas and live bullets were used” by National Intelligence and Security Service (NISS) agents against protesters.
He added that army soldiers had provided sanctuary for protesters within their compound.
“It is pointless for Omar Bashir to continue using his thugs to get us off the streets as we are not going anywhere.”
At least two soldiers are reported to have died since the demonstrations outside the army HQ began on Saturday.
Previous attempts to break up the crowds have also led to reports of soldiers intervening to protect protesters from NISS agents.
There have been international calls urging the government to refrain from using force against civilians. President Bashir has called for talks to end the crisis.
The country’s interior minister said on Monday that seven protesters had been killed and 15 injured, while 42 members of the security forces had been injured. He added that almost 2,500 people had been arrested.
Why are they protesting?
Protests against Mr. Bashir, who has governed Sudan since 1989, have been underway for several months.
The protests were originally sparked by a rise in the cost of living, but demonstrators are now calling for the president to resign.