Watch: Reporter breaks down on live TV while covering Gaza Strip fighting

GAZA CITY ( CNN) – Officials say hundreds of people have been killed since Israel announced a ground operation in the Gaza Strip.

The Gaza Health Ministry says about 550 Palestinians have been killed.

In all, 25 Israeli soldiers have died, including three believed to have been killed by friendly fire.

Two of the deceased were dual Israeli-American citizens.

The U.S. State Department says Max Steinberg, from California, and Sean Carmeli, from Texas, were killed during fighting.

“While the IDF takes every possible measure to minimize civilian casualties, Hamas and its deliberate tactic of embedding terrorist activities within the urban environment is ultimately responsible,” the IDF said in a statement.

Israel also blames Hamas for other civilian deaths in Gaza, saying the group has encouraged people to stay in their homes despite repeated warnings from Israel in advance of airstrikes.

President Barack Obama announced that Secretary of State John Kerry will “push for an immediate cessation of hostilities.”

A reporter for Al-Jazeera broke down on live television while talking about the situation in his hometown, near the Gaza Strip.