Four UN observers dead in Lebanon

Four UN observers killed in south Lebanon when their position was hit by an Israeli airstrike. This, despite repeated warnings by the UN to the IDF to stay away from their position. Kofi Annan rightfully suggests it was deliberate. I have a hard time believing that it wasn't.

My question is, if we are correct in assuming that the attack was deliberate, what was Israel's interest in carrying out the attack. It mjust have been pretty strong, as they would have known that huge negative repersuccsion would have arisen from the debacle? Is there maybe something they didn't want the observers to observe?