Protesters in Sudan's capital Khartoum have used burning tyres and stones to hold off police attempts to end demonstrations against government austerity measures.
Police were ordered to act immediately to end the unrest.
The BBC reports Sudan's economy has been in trouble since South Sudan ceded last July, taking three-quarters of all oil production with it.
The protests began on 16 June, triggered by government cuts to fuel subsidies and other spending.
They spread throughout Khartoum on Friday, when demonstrations broke out in several places despite the presence of riot police. Large numbers of arrests are reported.