Police continue to encounter rocks thrown by angry citizens, and gunfire from gangs who do not appreciate police presence. The gangs have learned to operate in small groups. Anything larger attracts large numbers of peacekeepers, who have armored vehicles, helicopters and a lot more firepower. Gangs have attacked NGOs and will rob relief workers if armed guards are not present. Peacekeepers and police make raids, using hundreds of armed personnel, against known gang hangouts. Dozens, or hundreds, of suspects are sometimes hauled away for questioning.