It became obvious very soon after the distribution commenced that the 'orderly' part of the event was under threat. There were raised voices in teh crowd, and that was very quickly followed by some scuffles: and then it happened, some began throwing rocks at the NGO personnel and the UN Military Escort. When the first rock hit a Brazilian UN Soldier on his blue helmet you could tell that this was not going to be a fair fight!
The UN Militia quickly surrounded the NGO personnel and escorted them to their vehicles and down the cleared exit route as the first shots rang out. Firing into the air the crowd very quickly got the message - the distribution was over. (No one was hurt.)
So what happened? Allegedly (no doubt actually) certain 'business men' approached a number of IDPs and offered to buy their vouchers for between $5 and $7 each. Some had bought 10 or more vouchers - unfortunately they didn't know, and didn't think to ask, what the distribution items were. When they discovered that their gamble had cost them, they were, shall we say, unhappy.
Lessons to Learn: As The Salvation Army has always said: Gambling is not a good habit to get into. (Especially not if you take your losses out on heavily armed Brazilian soldiers after their team has lost the World Cup - Not Happy, Jan!) And, maybe you should get yourself a blue helmet!