Heavily armed police patrol Khartoum's main streets
Police beat and teargassed students protesting in Sudan's Sennar State, the latest in a series of short-lived demonstrations partly inspired by uprisings in Tunisia and Egypt, witnesses said.
Around 200 students, protesting against price rises and calling for change, tried to rally outside Sennar University on Thursday afternoon, before officers moved in with batons and then surrounded the compound, witnesses told Reuters.
Sudan has used armed riot police to disperse a series of demonstrations by young Sudanese across the north of the country in recent weeks.
Protests earlier last month focussed on food prices and human rights abuses and broadened to include calls for political change after images of massed protests in Cairo, Tunis and other cities were broadcast across the world.
The protests, many around universities, have so far not been supported by wider parts of the population and have failed to gain momentum.
Also on Thursday police arrested dozens of people near the scene of a planned protest in the capital's Khartoum North suburb, said witnesses. The demonstration, which had been publicised on the internet, did not take place.
Police set up road blocks in and around Khartoum to search cars and lorries overnight. A Reuters witness saw officers even checking inside bags of vegetables in one vehicle on the road from Khartoum to the town of Kosti.
As part of a wider crackdown on opposition voices, officers arresting 10 journalists from Sudan's Communist Party newspaper on Wednesday and detained opposition Islamist Hassan al-Turabi and 12 of his party officials last month.