Protesters in Berkeley, California, threw bricks, rocks and pipes at police, who fired tear gas and smoke canisters to quell the crowds.
Several officers were injured, and buildings and cars were vandalised or looted, said police spokeswoman Jennifer Coats.
"Several splinter groups broke off and began hurling bricks, pipe, smoke grenades, and other missiles at officers," Coats told AFP.
"Numerous officers were struck, and one officer was struck with a large sandbag and treated at a local hospital for a dislocated shoulder," she said.
More From This Section
Akai Gurley, 28, father of a two-year-old daughter, was killed when a police officer opened fire in a dimly lit staircase at a Brooklyn apartment building where he was walking with his girlfriend.
Friends and relatives filed past Gurley's open gray casket to pay their respects at the Brown Memorial Baptist Church, before the lid was closed and a huge spray of red and white flowers was placed on top of it.
Mourners heard a rallying cry for justice at Gurley's funeral.
Activist Kevin Powell, who delivered the eulogy, thanked Mayor Bill de Blasio and the city of New York for covering the costs of the funeral and issued a passionate plea for change.
"Akai was innocent, innocent, innocent," he told the mourners.
"This is modern-day lynchings, over and over again. Akai Gurley was simply the latest victim of this," he said, calling for homicide charges to be brought.
"Let's do everything we can to prevent any more situations like this," he said.
Rev Clinton Miller echoed the call, saying that clergy and activists would work together to ensure that justice would prevail.
"We ask that you would allow brother Akai's name to live forever in our hearts as we continue to fight for what's right in this country and this world," he said. "We will all work together to pursue justice."