Israeli Defense Minister Ehud Barak promised a full investigation of what happened Thursday at the Egyptian-Israeli border, and said Israel regrets the deaths of the three Egyptians. His comments were seen as less than an apology for Israel's actions while pursuing militants from Gaza who had staged attacks in southern Israel, and public reaction was swift here in Cairo. Angry street protests outside the Israeli embassy in Cairo have been going on for several days, and the Egyptian press has mounted a war of words against the Jewish state. An Egyptian army checkpoint protects the Israeli embassy in Cairo's Giza district, but hundreds of protesters tried to break those barriers early Saturday. The crowd chanted slogans calling for expulsion of Israel's ambassador in Egypt, and demanded suspension of a controversial agreement with Israel for the sale of natural gas