JERUSALEM — Prime Minister Benjamin Netanyahu said on Sunday that Israel knew “for a fact” that the kidnapping of three Israeli teenagers was the work of the militant Islamic movement Hamas but held the Palestinian Authority responsible, arguing that the abduction proved that the world was wrong to accept the Palestinian government formed this month with Hamas’s consent.

“Israel warned the international community about the dangers of endorsing the Fatah-Hamas unity pact,” Mr. Netanyahu said, referring to the secular Fatah faction led by the Palestinian president, Mahmoud Abbas. “The dangers of that pact should now be abundantly clear to all.” Speaking in English to galvanize international attention, he added, “This will not advance peace; it will advance terror.”

In the largest military operation in the West Bank in years, Israel arrested at least 86 Palestinians, many of them senior Hamas figures, over the weekend, and sent thousands of specialized troops into the area, limiting access to the city of Hebron. The executive committee of the Palestine Liberation Organization condemned Israel’s “racist” campaign, rejected Mr. Netanyahu’s “foul accusations” and referred to the kidnapping as “alleged,” according to Wafa, the official Palestinian news agency.

The teenagers, Eyal Yifrach, 19, and Gilad Shaar and Naftali Frankel, both 16, were last heard from Thursday night as they tried to hitchhike home from Jewish settlements in the West Bank where they study in yeshivas. The growing search for them and their captors further destabilized Israeli-Palestinian relations, and challenged the new Palestinian government’s ability to hold together disparate political factions and reunite the West Bank and Gaza after a seven-year split.