The bombs used in the Israeli strike that killed dozens of Palestinians in a camp for displaced people in Rafah, Gaza Strip, on Sunday were made in the United States.

Munition debris filmed at the strike location the next day was remnants from a GBU-39, a bomb designed and manufactured in the United States, the Times found.

U.S. officials have been pushing Israel to use more of this type of bomb, which they say can reduce civilian casualties.

The key detail in the weapon debris was the tail actuation system, which controls the fins that guide the GBU-39 to a target, according to Trevor Ball, a former U.S. Army explosive ordnance disposal technician, who earlier identified the weapon on X.

The weapon’s unique bolt pattern and slot where the folding fins are stowed were clearly visible in the debris, Ball said.

The munition fragments, filmed by Alam Sadeq, a Palestinian journalist, are also marked by a series of numbers beginning with “81873.” This is the unique identifier code assigned by the U.S. government to Woodward, an aerospace manufacturer based in Colorado that supplies parts for bombs, including the GBU-39.

At least 45 people in Kuwaiti Al-Salam Camp 1, which was built in early January, were killed by the blast and subsequent fires, according to the Health Ministry in Gaza. More than 240 were wounded.

U.S. officials have been encouraging the Israeli military for months to increase the use of GBU-39 bombs in Gaza because they are generally more precise and better-suited to urban environments than larger bombs, including U.S.-made 2,000-pound bombs that Israel routinely uses. President Joe Biden said this month that the U.S. was pausing a delivery of the larger bombs.