Khartoum (AFP) – Sudanese demonstrators called President Omar al-Bashir a "killer" on Saturday, the sixth day of protests sparked by fuel price hikes in a nation already burdened by economic pain and war.
The latest protest came as reformist members of Bashir's National Congress Party told him that the deadly crackdown on demonstrators betrayed his regime's Islamic foundations.
"Bashir, you are a killer," shouted about 2,000 men, women and youths after the burial of Salah Mudathir, 28, shot dead during a protest on Friday and hailed by demonstrators as a martyr.
"Freedom! Freedom!" they chanted.
Authorities say 33 people have died over the past week, but activists and international rights groups say at least 50 were gunned down.
An AFP reporter saw state security agents round up six people and put them into pickup trucks after police fired tear gas to disperse the demonstrators on Saturday.
On Friday, the interior ministry said 600 people had been arrested since the beginning of the protests "for participating in acts of vandalism".
Mudathir was an atypical protester as most are from Khartoum's underclass, an analyst said.
"Now you have neighbourhoods revolting," said Magdi El Gizouli, a fellow at the Rift Valley Institute.
"These are the protests of the voiceless" who have no prospects in the mismanaged nation's bleak economy, Gizouli told AFP.
Saturday's protest occurred after thousands of mourners walked through the streets of the wealthy Mansheeya neighbourhood escorting an ambulance carrying Mudathir's body, one witness said.
Mudathir, a pharmacologist, belonged to a family that is prominent in business and politics.
"He was killed by a bullet to the heart" while he demonstrated, a cousin told AFP.
Police did not release the victims' names, but said "unknown shooters" gunned down four civilians during largely peaceful demonstrations which were dispersed with tear gas after Friday prayers in Khartoum.
Demonstrations began last Monday after the government scrapped fuel subsidies, leading to soaring prices.
The government measures, which almost doubled pump prices of gasoline and diesel, have had a severe impact on civilians, the 31 ruling party reformers said in a letter to Bashir, which they made public.
The package of economic measures was not presented to parliament and citizens had no chance to give input peacefully, they added.
"The package that was implemented by the government, and the crackdown against those opposed to it, is far from mercy and justice and the right of peaceful expression," they said.
The powerful National Intelligence and Security Service, a bulwark of the regime that operates separately from police, has been involved in the protest crackdown.
It was key to suppressing smaller-scale nationwide protests sparked by high food and fuel prices in June and July last year.
At that time there was no mass loss of life when authorities tear-gassed and rounded up demonstrators.
But Gizouli insists those protests were different, driven by students and activists rather than ordinary Sudanese.
The Sudanese Journalists' Network, an unofficial group of reporters who demand freedom of speech, announced that its members would stop work from Saturday because of official attempts to censor coverage of this week's protests.
"We see the killing of our people and we cannot ignore this," said a statement from the group, which claims 400 members.
Text messages referring to the Friday protests were held up in transmission for several hours and received only early on Saturday.
The demonstrations began Monday south of Khartoum in Wad Madani, capital of the decaying agricultural heartland state of Gezira.
Rallies later spread to Nyala, the battle-scarred capital of troubled South Darfur state, and to Khartoum itself.
"The people want the fall of the regime," protesters have chanted in Khartoum, echoing the refrain of Arab Spring rallies that toppled several regional governments in 2011.
Massive protests in Sudan have brought down governments twice before, in 1964 and 1985, and late last year the government said it had disrupted an attempted coup.
The alleged leader of the plot, retired armed forces Brigadier Mohammed Ibrahim, signed the ruling party reformers' letter. Bashir pardoned him and the other plotters earlier this year.
Sudan falls near the bottom of a United Nations human development index measuring income, health and education, and it ranked 173 out of 176 countries in Transparency International's index of perceived public sector corruption last year.
Analysts say a major portion of government spending goes to the military and security agencies.
The military is fighting two-year-old rebellions in South Kordofan and Blue Nile states, where insurgents are allied with rebels from the far-west Darfur region.
That alliance in April widened its offensive to topple the government, while violence has also worsened in Darfur this year.
Bashir is wanted by the International Criminal Court for war crimes, crimes against humanity and genocide allegedly committed in Darfur.