Two Israeli soldiers were killed "in combat" in southern Gaza on Sunday, according to the Israel Defense Forces.

Maj. Yaniv Kula, 26, and Staff Sgt. Itay Yavetz, 21, were killed in fighting in southern Gaza, according to the IDF. A reserve Israeli soldier in the Combat Engineering Heavy Equipment Unit was severely injured in the fighting in southern Gaza, the IDF also said.

The injured soldier, whose name was not released, was evacuated to a hospital for medical treatment and his family has been notified, according to the IDF.

Details were not released regarding how the Kula and Yavetz were killed, nor how the reserve soldier was injured.

-ABC News' Jordana Miller

An Israeli official confirmed to ABC News that a decision had been made earlier Sunday to close crossings into Gaza, halting aid from entering, but that the decision has since been reversed.

A political source familiar with the matter told ABC News that aid deliveries from crossings into Gaza were also temporarily stopped Sunday due to the bombing and that the Rafah crossing will remain closed for now.

“Due to the intense bombings and dozens of deaths on the Hamas side, Israel stopped truck traffic today, which will resume when the bombings end," the official told ABC News. "Rafah Crossing will only open when we see Hamas continuing to return the dead hostages at a reasonable pace.”

-ABC News' Jordana Miller

The Israel Defense Forces said Sunday that it has "struck dozens of Hamas terror targets" in Gaza.

"In response to Hamas’ blatant violation of the ceasefire agreement this morning, the IDF struck dozens of Hamas terror targets across Gaza," the IDF said in a social media post. "The strikes targeted weapons storage facilities, firing posts, terrorist cells and additional Hamas terror infrastructure."

"In addition, the IDF struck and dismantled ~6 km of underground terrorist infrastructure, used to advance attacks against Israel, using over 120 munitions," the post continued.

In an earlier post Sunday, the IDF said the strikes were "in response to the blatant violation of the ceasefire agreement earlier today."

Hamas' military wing said that the body of another Israeli hostage has been found and can be handed over "if field conditions" allow.

"Today, we found the body of an Israeli captive during ongoing search operations. It will be handed over today if field conditions allow," the al-Qassam Brigades said in a statement.

"We emphasize that any Israeli escalation will hinder the search, excavation, and retrieval operations, which will delay the occupation’s recovery of the bodies of its dead," the statement continued.

The bodies of 16 hostages remain in the Gaza Strip, according to the latest information from the Israeli government.

The State Department said in a statement published Saturday that the United States has informed the guarantor nations of the Gaza peace agreement of "credible reports indicating a ceasefire violation" by Hamas against Gazans.

The agency warns that should Hamas proceed with the attack, measures will be taken.

"The United States and the other guarantors remain resolute in our commitment to ensuring the safety of civilians, maintaining calm on the ground, and advancing peace and prosperity for the people of Gaza and the region as a whole," the State Department said.

-ABC News' Mariam Khan