Clashes reported as Sudanese protesters march on presidential palace

Thousands of protesters calling for the resignation of Sudanese President Omar al-Bashir  on Tuesday were met with rounds of tear gas fired by police as they attempted to reach the country's presidential palace in Khartoum.

Large numbers of security forces were deployed across much of the capital in anticipation of the march, with soldiers riding in all-terrain vehicles, activists reported.

The protest was called by an umbrella of independent professional unions and supported by the country's largest political parties, Umma and the Democratic Nationalists.

The organisers want to submit a petition demanding that Bashir, who has been in power since a 1989 military coup, step down.

The march follows nearly a week of protests initially sparked by rising prices and shortages of food and fuel, but which later escalated into calls for Bashir to go.

It also comes after the Sudanese leader visited the region and addressed a large crowd of supporters at a rally.

There were no immediate reports of casualties.

Angry crowds have taken to the streets in a dozen cities across the economically troubled country since Wednesday after the government tripled the price of bread. 

The authorities say that eight protesters have been killed in clashes, but Amnesty International has put the death toll at 37.