KHARTOUM: At least one protester died in an anti-government demonstration on Thursday as thousands of people rallied across Sudan calling on President Omar al-Bashir to resign.

The east African nation has been rocked by more than a month of deadly protests triggered by the Bashir government's decision to triple the price of bread.

Protesters chanting the movement's slogan of "Freedom, peace, justice" have been confronted by a crackdown that has drawn international condemnation, including from the United States which has warned Sudan it could damage moves to improve their ties.

The mushrooming demonstrations are widely seen as the biggest threat to Bashir's iron-fisted rule since taking power in an Islamist-backed coup in 1989.

The Sudanese Professionals' Association that is spearheading the protest campaign had upped the ante with a call for nationwide rallies on Thursday.

"One protester has died in Omdurman today," Amer Ibrahim, who heads a committee at the prosecutor's office that is investigating protest violence, told reporters without specifying how the victim died.

Hundreds of protesters demonstrated Thursday in Omdurman, where they clapped and whistled before hit by tear gas according to witnesses.

A doctors' committee linked to the SPA said two protesters had died on Thursday.

It said the protester killed in Omdurman was struck with "live ammunition," while another protester had died in detention.

The committee did not specify when the victim had been detained.

Ibrahim meanwhile said that a protester died from wounds sustained at demonstration on January 13 in Khartoum, without saying when they died.

"Until now 29 people have died in demonstrations," Ibrahim said. Rights groups have put the overall death toll at more than 40.

The SPA called for rallies in 17 places in Khartoum and Omdurman -- the capital's twin city on the west bank of the Nile River -- from where demonstrators were told to march towards the presidential palace on Thursday.

Hundreds of protesters began demonstrating in several areas of the capital, aiming to reach the palace but they were quickly confronted by riot police with tear gas, witnesses said.

"Let's die like martyrs or fight for their rights," shouted men and women as they took to the streets in Khartoum's eastern district of Burri -- a site of regular protests.

Several previous attempts to march on the presidential palace have been broken up by riot police firing tear gas.

'Will achieve our mission'

Hundreds of protesters chanting "freedom, freedom" and "revolution, revolution" rallied in Burri, blocking all roads leading to the district with tree trunks, iron pipes, rocks and burning tyres, witnesses said.

Thick black smoke from burning tyres and rubbish billowed into the sky from Burri.

"We will demonstrate. We will achieve our mission of overthrowing this regime," said a protester without revealing his identity for security reasons.

Witnesses said many policemen wearing masks and driving pick-up trucks patrolled the streets in several areas.

Anti-government rallies were also held in the Red Sea town of Port Sudan, in a village in North State, in the agricultural state of Gadaref and in the central city of Madani, witnesses said.

Hundreds of protesters chanting the slogan of the movement "freedom, peace, justice" demonstrated for hours in Port Sudan.

Several villages along the highway connecting Khartoum with Madani also saw protesters taking to the streets, while in Madani itself protesters chanting "Revolution, revolution" were met with tear gas.

US warning
Several businesses in Khartoum ordered their employees to leave before the protests began, while many schools saw few children attending classes.

The demonstrations come with Sudan battling an economic crisis driven by soaring inflation and a shortage of foreign currency.

The country's president has remained defiant and rejected the calls to step down, blaming the violence on "infiltrators" among the protesters.

Bashir has accused the United States of causing Sudan's economic woes, but his words have fallen on increasingly deaf ears as people have struggled to buy even basic foods and medicines.

The United States imposed a trade embargo on Sudan in 1997, which was only lifted in October 2017.

On Wednesday, Washington called for an investigation into the deaths of protesters, warning Khartoum that excessive force against demonstrators and intimidation of the press and activists would jeopardise relations.

"A new, more positive relationship between the United States and Sudan requires meaningful political reform and clear, sustained progress on respect for human rights," US State Department spokesman Robert Palladino said in a statement.