Authorities in Madrid say three city policemen have been injured when a crowd threw objects at them in a tense immigrant neighborhood of Spain's capital where violent protests followed the death last week of an African street vendor.

Spanish news agency Europa Press cites unnamed police sources as saying officers were checking the identity of a Senegalese street hawker when a group began insulting them Wednesday afternoon.

The report says the three officers were treated for their injuries and riot police were deployed to the central Madrid neighborhood of Lavapies.

Demonstrators last week rioted and threw stones at police after a 35-year-old Senegalese hawker died of cardiac arrest in the street. Controversy surrounded his death, with some Senegalese street vendors and activists criticizing police aggressiveness while clamping down on hawkers.