By Gabrielle Tétrault-Farber GENEVA (Reuters) -The United Nations agency for Palestinian refugees (UNRWA) said on Friday it had opened an investigation into several employees suspected of involvement in the Oct. 7 attacks in Israel by Hamas and that it had severed ties with those staff members. “The Israeli authorities have provided UNRWA with information about the alleged involvement of several UNRWA employees in the horrific attacks on Israel on October 7,” said Philippe Lazzarini, UNRWA Commissioner-General. “To protect the agency’s ability to deliver humanitarian assistance, I have taken t…