Just check that link, robomatic. Deir Yassin, like My Lai, is an incident that gets quoted because it was unusually well documented. It was not the only massacre of civilians in the course of the ethnic cleansing of Arabs which occurred at that time.

The reason why people fled from their homes at that time were the same reasons people become refugees in most wars, the same reason that, I imagine, most of us would consider doing the same in a similar situation. They feared getting killed, either in crossfire, or in deliberate massacres of one sort or another. News about Deir Yassin was one factor that reinforced this process, and there can be no doubt that those who carried out the massacre and colluded in it had this intention in mind.

It was the same reason why enormous numbers of Lebanese and Israelis fled to safer areas during the war that has just been halted - with the difference that in the earlier case the refugees were not allowed to return home, as they had every right to do. That is what makes it "ethnic cleansing".