Police in Senegal's capital, Dakar, have fired teargas at hundreds of protesting street vendors who threw stones and burned tyres.
Police used tear gas and truncheons to disperse the rioters
The clashes came in response to police enforcing a new government policy to remove the vendors.
Demonstrators blocked main streets and attacked cars. At least fifteen people were arrested - making it the most serious riot in Senegal for years.
Thousands of people earn a living peddling goods on Dakar's streets.
The violence broke out shortly after trades unions held their own demonstration against rising food and fuel prices.
Plumes of smoke
Old tyres, plastic rubbish containers and wooden stalls were used to light fires along Dakar's busy central business district.
Plumes of black smoke rose above the city centre as riot police pursued youths down side streets choked with tear gas.
Disturbances reportedly spread to neighbouring residential quarters.
Police began evicting the thousands of street vendors on Thursday, three days after President Abdoulaye Wade sought an end to informal trading in the city.
He said uncontrolled street vending had cost the country some 125m Euros because traffic jams were putting off investors.
Dakar is to host the 57-nation Organisation of Islamic Conference (OIC) summit in March, and ahead of the meeting the city has been undergoing a major facelift - new hotels, conference rooms, bridges and roads are all being built.