Israel said on Sunday its troops would remain for many months in refugee camps in the occupied West Bank after its intensifying military operation displaced tens of thousands of Palestinians living there. The military began a major raid in the West Bank's north a month ago, just after a truce went into effect in the Gaza Strip. The West Bank offensive has gradually expanded, spanning multiple refugee camps near the cities of Jenin, Tulkarem and Tubas. Three of the camps, Jenin, Tulkarem and Nur Shams, "are now empty of residents", Defence Minister Israel Katz said in a statement. He put the number of forcefully displaced Palestinians at 40,000, the same figure provided by the United Nations which said the offensive has so far killed at least 51 Palestinians including seven children, and three Israeli soldiers.