They formed a wall with their bodies to defend the barricades from the latest assault by the military against the movement for democracy and change.
And the protesters were cheered by news that aviation workers and flight controllers are preparing a strike that will close the country’s airspace if the military refuse to step aside.
Shots had been fired on Wednesday as soldiers tried unsuccessfully to clear barricades. Protesters said 14 people were wounded. Similar violence on Monday left five people dead.
The Alliance of Freedom and Change, the opposition umbrella group, said that the killings were carried out by the military’s Rapid Support Forces.
This is a key moment for the revolt.
On Tuesday the Sudanese Professionals Association that has been at the centre of the uprising and the strikes released a statement saying, "Despite the heinous act of the murderous defunct regime, our people have never lost hope in passing to a new era of freedom, peace, and justice. To attain that goal, we are now heading towards civil disobedience and a general political strike.
"For this purpose, we are calling upon all revolutionary entities to get in touch with the strike committees in the various professional, artisan, and service sectors to sign up."
Sudan’s military rulers last week suspended talks on moving the country towards civilian rule for three days. They want to demobilise the movement that toppled dictator Omar al-Bashir last month.
Talks began again on Sunday.
The military and the opposition are agreed on a three-year transition to a fully civilian administration.
A presidential council and a 300-member legislature would run the country until elections are held.
Two-thirds of the seats in the legislature would go to the opposition.
But both the military and the opposition want a majority of seats on the 11-member presidential council. This would be the top tier of government.
The six-month revolt against al Bashir and his followers has seen inspirational organisation by millions of people.
They must not settle for a deal that leaves the military holding on to their economic and political power.
Recent weeks have seen powerful strikes alongside sit-ins and marches across the country.
Last week teachers began a sit-in at the offices of the department of education in El Geneina, capital of the West Darfur region.
This was to strengthen their indefinite strike for civilian rule and changes in schools.
Staff of phone and internet firm Sudatel organised a massive demonstration in Khartoum to protest over the killings. And they demanded the speedy dismissal of Sudatel’s director general, describing him as “an agent of the former regime”.
The next day workers at hospitals in Ad Damazin and El Roseiris in Blue Nile state struck in protest against a military attack on doctors. Petroleum workers protested on Sunday
Those involved in the protests and the strikes have to form their own democratic centres of power—workers’ councils—which draw in wider layers of the population.
Every day it’s becoming more urgent to set up and coordinate such bodies.