BUJUMBURA, Burundi (AP) — Carrying prized possessions, scores of people fled Burundi's capital Saturday before a looming security crackdown that many fear will be a wave of violence.

A government-issued deadline to turn in illegal weapons or face extraordinary police action expires midnight Saturday and President Pierre Nkurunziza, whose decision to extend his rule sparked the country's current crisis, has urged the security forces to use all means necessary to restore order.

But many here blame the security forces for a series of killings that has raised international concern and convinced residents in some volatile areas to flee their homes.

At least 198 people have been killed in Burundi since late April, when President Pierre Nkurunziza announced his bid that was ultimately successful for a third term in office, according to U.N. officials. At least 13 people have died in the past week, with many coming from Bujumbura neighborhoods known as opposition strongholds. More than 200,000 people have fled Burundi fearing violence.

Among the victims is Welly Nzitonda, the son of prominent human rights activist Pierre Claver Mbonimpa, who is himself in exile after an attempt on his life.

The U.S. on Saturday condemned the killing of Nzintonda — who according to a witness was arrested by police and whose body was discovered Friday in a pool of blood in an empty house in the capital — and said it was "gravely concerned" by ongoing violence in Burundi.

Fatou Bensouda, the prosecutor of the International Criminal Court, warned Friday of a worsening security situation and said perpetrators would face justice.

In Cibitoke and Mutakura, neighborhoods in northern Bujumbura that have been hotbeds of anti-government protests, some residents told The Associated Press Saturday they had no option but to seek refuge elsewhere. In order to leave their home areas they had to pass through search cordons mounted by the security personnel looking for illegal guns. Illegal weapons are guns owned by civilians who are not authorized to keep them.

Among those leaving their homes, some carried bed mats on their heads and children on their backs.

"Now I decide to leave as everyone is leaving. There is fear everywhere. But I still believe in God and all this will end," said Marguerite Bigira, an elderly woman who was among a group of people fleeing Mutakura.

Although the current violence appears to be political, Burundi has a history of deadly conflicts between the country's Hutu and Tutsi ethnic groups. Nkurunziza took power in 2005 near the end of a civil war in which some 300,000 people were killed between 1993 and 2006.

Samantha Power, the U.S. ambassador to the U.N., on Thursday quoted the president of the Burundian Senate, Révérien Ndikuriyo, as saying: "You tell those who want to execute the mission: On this issue, you have to pulverize, you have to exterminate — these people are only good for dying. I give you this order, go!"

Human Rights Watch said Saturday that in the last two days some neighborhoods in Bujumbura "have started to empty" as panicked people flee to areas where they consider less dangerous.

"Burundians take these warnings seriously, having seen relatives, friends, and neighbors shot dead by the police during nightly raids. Panic has set in, and some residents of Bujumbura have been packing up their belongings and fleeing," the group said in a statement Saturday. "The police have a duty to restore security and disarm people who have weapons illegally, and they can use lethal force when lives are at imminent risk. But that does not give them a license to kill."

Mutakura resident Philbert Nzinahora said that a family in Bujumbura's Carama neighborhood, seen as more peaceful, has agreed to host his wife and children until it is safe for them to return home. He will not accompany them, in order not to compromise their safety, he said: "I will find another place to go."