Jerusalem - Israel's security service has barred the Prime Minister, Mr Ehud Barak, from appearing at a memorial for Yitzhak Rabin next week because of fears of attacks, a newspaper reported yesterday. Mr Barak may instead address the open-air gathering on November 4th by TV link from a building near the Tel Aviv square where Rabin was murdered by a Jewish extremist exactly four years before, the Hebrew newspaper Maariv reported.