Israeli soldiers carry the five coffins holding Israeli citizens Itzik Colangi, 28, Amir Menashe, 28, Maor Harosh, 25, Elior Price, 26, and Kochava Shriki, 44, killed in a suicide bombing attack in Bulgaria July 18, at a ceremony after the bodies arrived at Ben-Gurion Airport. Photo: Amos Ben Gershom/GPO/FLASH90.

The amount of telephone calls between Lebanon and Burgas saw an uptick during the two months before the July 18 suicide bombing of a tour bus carrying Israelis in the Bulgarian city, the New York Times reported.

Israel—which from the outset accused the Lebanon-based and Iran-funded Hezbollah terrorist group of orchestrating the bombing—has learned of an even greater spike in those calls for the three days prior to an attack that killed five Israelis and their Bulgarian bus driver, according to the newspaper.

“We know the sources in Lebanon,” a senior Israeli government official told the Times.