Police said there were a number of lines of inquiry but one theory was that the shooting was in reprisal for an earlier gun attack.

BBC: Imani Green

Tim Isles, another OSCE observer, said the attack could be a reprisal for other skirmishes that have taken place in the past week.

CNN: Serb troops cross into Albania, officials say

Israel said its attack on the Syrian base was a reprisal for the killing of one of its soldiers on the Lebanese-Israeli border on Saturday by Syrian-backed Hezbollah guerrillas.

CNN: Israel lifts Gaza roadblocks

The Sierra Leoneans also attack Guineans, largely, it seems, in reprisal for operations by Guinean troops attached to the West African peacekeeping force, Ecomog, which intervened in Sierra Leone.

ECONOMIST: Guinea