United Nations officials say Israel has blocked a U.N. fact-finding mission to the Gaza Strip.

Former South African Anglican archbishop and Nobel laureate Desmond Tutu was to begin leading a six-member team over the weekend in the northern Gaza town of Beit Hanoun.  The aim of the mission was to investigate the killings of 19 civilians in an Israeli artillery barrage last month.

U.N. officials said Monday Israel refused to grant Tutu and his team the necessary travel clearance. 

The Associated Press quoted an Israeli Foreign Ministry spokesman as saying a final decision on allowing the trip had not been made.  Israeli officials had expressed concern that Tutu's mission was only concerned with investigating alleged human rights violations committed by Israel, and not also by Palestinian militants.

The 47-nation U.N. Human Rights Council authorized the fact-finding mission on November 15.  It asked Tutu to assess the situation of victims, address the needs of survivors and make recommendations on ways to protect Palestinian civilians against further Israeli attacks.

Some information for this report was provided by AFP, AP and Reuters.