Bricks were thrown and fires lit outside Stratford bus station and Forest Gate police station in London.
Protesters allege Edir Frederico Da Costa, 25, was "brutally beaten" by Met Police officers earlier this month.
The Independent Police Complaints Commission (IPCC) is investigating the treatment of Mr Da Costa, who died six days after he was stopped by police.
Borough Commander Supt Ian Larnder stood in the middle of a group of protesters trying to answer their questions and calm tensions.
One protester rode his motorbike up to the police line and revved his engine in front of officers.
Another motorcyclist turned his bike towards the officers and span his wheels so smoke blew towards them.
Firefighters, protected by police, hosed out a fire which had been started in a bin in Richmond Road. Bins were also set alight near a McDonald's in Romford Road.
Bricks had been ripped from a wall and thrown at police.
Family campaigners said the violence was not coming from them and it had been set up as a peaceful march.
The police said there had been no arrests but some officers suffered minor injuries.
The force added that the number of protesters was starting to dwindle just before 23:00.
Mr Da Costa, known by friends as Edson, died on 21 June, six days after being stopped in a car in Woodcocks, Beckton, in Newham, east London.
Campaigners claim that his neck was broken and he suffered head and other injuries after he was stopped in a car, containing three people, by Met officers.
The IPCC said a preliminary post-mortem examination, carried out on Thursday, indicated there were no spinal injuries caused by police.
Transport for London said that from just before 18:00 there had been "a number of bus diversions at police request" due to the demonstration at Stratford.
Protesters have faced off with police in a demonstration over the death of a man after a traffic stop.