The fatal stabbing of the 34-year-old anti-fascist activist and rapper Pavlos Fyssas in Athens early on September 18 is a stark reminder that extremist violence in Greece is an alarming problem. The news of the killing was saddening but not surprising.

Greece has had an epidemic of violence over the past few years. Much of this violence targets foreigners, but attacks on LGBT people have also been reported. In research I conducted in 2012, I spoke to dozens of victims of xenophobic violence who had been beaten, kicked, and chased down the streets of Athens by gangs of Greeks. Victims included migrants and asylum seekers, pregnant women, and children.

During my research for Human Rights Watch I found that most attacks take place at night, on or near town squares. The attackers work in groups, and often wear dark clothing and obscure their faces  with cloth or helmets. Some of them arrive and flee on motorcycles. Attackers also often wield clubs or beer bottles as weapons but bare-fisted attacks are not uncommon.

No one has been convicted for racially motivated violence under Greece’s 2008 hate crime statute.Alandmark trial that began in September 2011 of two men and a woman for stabbing an Afghan asylum seeker, Ali Rahimi, has been postponed nine times. The next hearing is scheduled for January 22. The woman defendant ran unsuccessfully for office in last year’s national elections on the Golden Dawn ticket. The party denies any role in this and other violent attacks.

Despite clear patterns to the violence and evidence that it is increasing, the police have failed to respond effectively to protect victims and hold the attackers to account.

Greece has taken some positive steps recently with the creation of specialized police units to tackle racist violence across the countryand the appointment at the Athens First Instance Prosecutor’s Office of a specialized prosecutor on hate crimes. And some arrests have been made. Butmuch more needs to be done.

It is vital for the government to show leadership by publicly condemning violence and indicating that there will be zero tolerance for vigilante violence against migrants. The authorities need to deploy adequate numbers of police officers to known hot spots to prevent attacks and to arrest attackers in the act. The government also should improve the investigation and prosecution of hate crimes by police and prosecutors through training, better guidelines, and a centralized police database. And it should ensure that victims never face obstacles for reporting a hate crime.

During meetings with the government, we have repeatedly warned that unchecked violence against migrants is bound to spread to the rest of the society.  The government needs to stop turning a blind eye to extremist attacks. It needs to ensure that everyone is protected from violence no matter what their status and that people who carry out hate crimes are brought to justice.

Eva Cossé monitors Greece for Human Rights Watch.