Sudanese government has pointed to "fake" victim photos and foreign interference in defence of a deadly crackdown on protesters, which drew fresh criticism from inside the ruling party as rallies continued.

With reporters complaining of stepped-up censorship, numerous videos and photographs purporting to show bloodied victims have circulated on YouTube, Facebook and other social media since the demonstrations began eight days ago, sparked by a rise in fuel prices.

"Most of the pictures on social media websites are from Egypt," Sudan's Interior Minister Ibrahim Mahmoud Hamed told a news conference on Monday, where he and other officials were confronted by a Sudanese reporter.

Why are you always telling lies? The people are killed by NCP militia Bahram Abdelmoneim, journalist,

"Why are you always telling lies? The people are killed by NCP militia," said journalist Bahram Abdelmoneim when he got up to ask a question.

Abdelmoneim, of Al Youm Al Taly newspaper, was referring to the ruling National Congress Party.

He was unreachable by telephone later after colleagues said he had gone to a meeting with state security agents.

'Criminal' attacks

Authorities say 34 people have died since petrol and diesel prices jumped more than 60 percent on September 23, sending thousands into the streets in the worst urban unrest in the history of Sudan's President Omar al-Bashir's 24-year reign.

Activists and international human rights groups said at least 50 people were shot dead, most of them in the greater Khartoum area.

The real toll was difficult to determine, but "could be as much as 200", a foreign diplomat told AFP news agency on condition of anonymity.

Khartoum governor Abdel Rahman Al-Khidir told the news conference that police only opened fire to defend their stations.

The interior minister said "criminal" attacks, separate from the peaceful protests, had been launched on police facilities and petrol stations.

"We know that overseas foundations are supporting these criminal activities," Hamed said, adding that about 700 people have now been arrested.

Fresh protests

Eight days after demonstrations began in a rural area south of the capital, rallies continued on Monday.

About 200 called on Monday night for freedom as they marched through the streets of Khartoum's Burri area for a third day to express support for the "martyr" Salah Sanhouri, 28, a pharmacist.

He was shot dead during a protest on Friday, they said.

In Khartoum's twin city of Omdurman witnesses said about 300 people demonstrated at the main bus station until police tear gassed them.

Police fired tear gas into the campus of Ahfad University for Women, where between 150 and 200 students were demonstrating "against the government and things like that," university president Gasim Badri told AFP.