Protesters have clashed with police across Israel following the funeral of a teenager of Ethiopian descent who was shot dead by an off-duty officer.
Thousands took to the streets of several cities on Tuesday, blocking roads with sit-ins and burning tyres.
A police spokesman said 111 officers were wounded during the disturbances and that 136 people were arrested.
The prime minister acknowledged the Ethiopian community faced "problems" but told protesters not to block roads.
Tens of thousands of Ethiopian Jews were brought to Israel in the 1980s and 1990s. They say they have faced systematic discrimination, racism and a lack of empathy for their hardships ever since.
The killing of 18-year-old Solomon Tekah near Haifa on Sunday caused outrage among the Ethiopian community, with one member of the teenager's family accusing the off-duty police officer of murder.
A police statement cited the officer as saying he had tried to intervene in a fight between two groups of youths. After he identified himself, the youths began throwing stones at him and he opened fire after "feeling that his life was in danger", the statement added.
However, Israeli media cited witnesses as saying the officer was not attacked.
The officer has been placed under house arrest and questioned by investigators.
On Tuesday afternoon, protesters gathered at road junctions in cities including Haifa, Tel Aviv and Jerusalem.
"We'll do whatever we can to make sure police will stop killing people because of their skin colour," one protester told AFP news agency.
"We don't know if this is going to happen again or not," he added. "But we need confidence that the state or police give us guarantees it won't."
The police force said officers initially exercised restraint and allowed the protesters to block the roads, but that they had to intervene once the protesters started throwing Molotov cocktails and stones, burning tyres, and damaging property.
Officers fired tear gas and stun grenades to disperse the protesters overnight.
Emergency services said 50 people received medical treatment, including protesters, police officers and bystanders, according to the Haaretz newspaper.
Prime Minister Benjamin Netanyahu said in a statement that he mourned "the tragic death of young Solomon Tekah", and that he embraced the teenager's family and the Ethiopian community.
"I know that there are problems that need to be solved. We have worked hard and need to work more to solve them," he added.
"But I ask of you one thing. Stop blocking the roads. We are a nation of law; we will not tolerate the blocking of roads. I ask you, let us solve the problems together while upholding the law."
President Reuven Rivlin called for an end to the violence and an investigation into Solomon Tekah's killing, saying: "It is upon us to prevent the next death. The next humiliation. We are all obligated to this."
Protesters also blocked a highway in Tel Aviv in January, after a police officer shot and killed a mentally ill Ethiopian man who ran towards him brandishing a knife. Police said the Yehuda Biadga, 24, had "posted a clear and present danger", but his family said the officer had used excessive force.