FOR Serb thugs, finding easy targets to harass and to intimidate is not difficult. Potential victims in the Serb-held Sarajevo district of Grbavica are few in number and are cowering in their apartments, waiting at night for a malicious knock on their door.
For weeks they have been subject to what United Nations officials describe as a reign of terror at the hands of criminals and their own Bosnian Serb authorities, who want them to flee before the area is transferred to the Muslim-led Bosnian government next Tuesday.
To combat the growing lawlessness, a UN police force has increased its presence and NATO-led peacekeeping troops are stepping up patrols. But the moves are late in coming, residents say, and they are terrified. Already, the majority of the Serbs who withstood 3-1/2 years of war here have left. The UN expects that only a few hundred people - out of a population of 5,000 - will remain.
Grbavica is the last of five Sarajevo districts to change hands as part of the Dayton peace agreement, but the oppressive air that hangs in the war-damaged high-rise apartment buildings makes the work of roving gangs easier. Other suburbs have been burned by fleeing Serbs, and here the fires are starting.
''We've heard that people want to create a spectacle, so that Sarajevo can see Grbavica burn,'' says one Serb woman, who still lives with her husband in an apartment overlooking the Bosnian capital. Their building and all the others on the hill are said to be pinpointed by the gangs for bombing or the torch. They talk quietly of putting blankets over the windows so any grenades thrown from outside will drop directly on to the floor. They are not armed. The thugs, they are warned, can even make a silencer for their pistols from a soda bottle. No one is safe.
''I don't think there is anything left to burn, and in some places they have even taken up the parquet floor,'' she says, while fumbling to organize fire extinguishers and flashlights. The electricity has been turned off by the Serb authorities, and the natural gas supplies fluctuate.
The couple's decision to stay is impossible to hide and makes them vulnerable. Every other apartment in the building has been stripped and abandoned. Their doors are ajar and debris litters the floors. The couple's solid door looks more and more like a target.
Most of their neighbors have fled because they fear revenge from the Bosnian government for the four-year Serb siege of Sarajevo. The couple says they have nowhere else to go. ''We are afraid of peace,'' the woman says.
Nighttime action by the thugs has been most heavily directed at minorities, the handful of Muslims and Croats who have survived years of nationalist Serb rule. The UN police and IFOR, the 60,000-strong peace Implementation Force, appear powerless to stop the intimidation.
The International Police Task Force, or IPTF, has boosted its strength from 30 to 80 officers in the past week, and operates 20 patrols at any given time. But their mission is strictly limited.
''The international police have no authority, and have the misfortune of having 'police' in their name. They are only a monitoring force,'' says one UN official. ''In Grbavica we are dealing with only 30 to 40 thugs. All it would take is to start checking cars for weapons and kick them out.''
The IPTF station in Grbavica has registered more than 600 people who want to stay.
''I know the international community has given a lot of guarantees, but they must give more,'' says one angry resident. ''People must feel that guarantee. Our police no longer function.''
The violence is politically motivated and designed to terrorize. In one incident, a Muslim woman doctor was persuaded to open her door when someone claimed to have a sick child. Two men wearing black outfits and ski masks forced their way in, threatened to kill her with a long knife, and robbed her, according to a relief worker.
She received another midnight call for help recently, but did not pull the barricades down from her door. It was another group of thugs.
The growing violence struck hardest last week at the elderly Sadeta Mehanovic, a Muslim woman who lived alone. Frightened neighbors heard two men break into her apartment, her screams for help while she was severely beaten, then the gunshot that killed her.