Image copyright AP Image caption The shooting of black teenager Brown in Ferguson led to often violent street battles between residents and police

A new US project studying police arrest data for racial bias has been awarded a $4.75m (£2.9m) grant, US Attorney General Eric Holder has announced.

The study will look at data from five cities and implement changes if police are using racial profiling in arrests.

Mr Holder said the cities, which have yet to be chosen, will serve as pilots to test strategies for building trust between police and communities.

This project comes after violent unrest in Ferguson, Missouri, last month.

Riots broke out after the police shooting of unarmed, black teenager Michael Brown, 18, on 9 August.

Eye-witnesses said Brown was trying to surrender when he was shot several times, though the police say he was killed after a struggle.

"The events in Ferguson reminded us that we cannot allow tensions, which are present in so many neighbourhoods across America, to go unresolved," Mr Holder said.

The project will be led by law enforcement experts from the John Jay College of Criminal Justice in New York, as well as Yale Law School, the Center for Policing Equity at the University of California and the Urban Institute.