The United States said Israel must make every effort to avoid civilian casualties. This came after the deadly strike that hit a refugee camp in Rafah, in which 45 people were killed, according to the Gaza Health Ministry.
Israel is facing a wave of international condemnation over the strike, both in the region and from the European Union, France and the United Nations.
"As we have made clear, Israel must take every possible precaution to protect civilians," a spokesman for the US National Security Council said in a statement.
"We are actively engaging the IDF and partners on the ground to assess what happened," the spokesman added.
The Gaza Civil Defense Agency said the strike sparked a fire that swept through a displacement center in northwest Rafah, near a U.N. agency facility for Palestinian refugees.
"The devastating images following the IDF strike in Rafah last night, which killed dozens of innocent Palestinians, are heartbreaking," the SNC spokesman said.
The Israeli military said it had launched an investigation into the strike, which it said was carried out on the basis of "accurate intelligence information" about two Hamas militants it said were killed.
The Israeli army launched the attack on Rafah hours after Hamas fired rockets into the Tel Aviv area, most of which were intercepted. / BGNES