The Israeli Prime Minister-elect, Ariel Sharon, has accused forces loyal to the Palestinian leader, Yasser Arafat, of being involved in bomb attacks against Israel. Three Israelis and a suicide bomber were killed in an attack yesterday in the city of Netanya. In a separate development, Mr Sharon has reportedly signed a deal with the Ultra-orthrodox Shas Party to join his coalition government. A spokesman for Shas said that his party had decided to enter the government because of the worsening security situation.