Israel said it sustained its first troop fatality Sunday in its offensive against Palestinian militants in Gaza, which has claimed more than 500 lives.

The Daily Mail reported Monday at least 512 people had died through Sunday, the ninth day of Israeli attacks dubbed Operation Cast Lead.

Officials said the unidentified Israeli solider died early Sunday when hit by mortar fire in northern Gaza's Beit Lahiya, CNN reported. It happened as troops pressed into Gaza overnight, taking control of a portion of the coastal strip, observers said.

In addition, to the fatality, 30 Israeli soldiers have been wounded, the Daily Mail said.

"Civilians are being killed ... shells are severing people's legs, shrapnel is going into people's bodies and into homes, a lot of people are being cut down. Everyone is terrified," the Daily Mail quoted an unnamed foreign doctor working for the Red Crescent as saying.

Israeli troops wrested control of the eastern section of northern Gaza, engaging in heavy battles with members of the Palestinian militant group Hamas, CNN reported. A statement issued by the Israeli military Sunday morning claimed dozens of Hamas fighters were "hit" in the fighting, although it did not say how many were killed, while Palestinian medical sources told CNN at least 21 were slain.

The same sources said four civilians were killed by shelling in Rafah in southern Gaza and five were killed near the Jebalya refugee camp, CNN reported.

Israeli military authorities said they targeted 45 Hamas locations overnight Sunday, including the Hamas intelligence headquarters.

As tens of thousands of protesters in European cities and world leaders called for an end to the invasion of Gaza, Israeli military officials told The New York Times their objective was "taking control" of the rocket launching sites Hamas has used to fire at southern Israel. They reiterated it is not their aim to fully reoccupy Gaza, as Israel did until 2005, the Times reported.