GAZA: Israel stepped up its ground assault in Gaza early on Friday pounding targets with artillery fire and using tanks and infantry.

Palestinian health officials said 23 Palestinians had been killed since Israel launched its ground offensive against the densely-populated strip of 1.8 million Palestinians on Thursday.

Gaza City resident Ebaa Rezeq told Al Jazeera that while Israeli soldiers remained near the buffer zone, air raids and shelling were continuing to terrify civilians. In one of the air raids, a building housing local media offices in Gaza City was struck by three bombs. Israel maintains that the offensive is to destabilise Hamas and "demilitarise" Gaza.

A video clip released by the military showed six tanks rolling in through the sand dunes of Gaza, after a soldier opened a border fence, and two long rows of foot soldiers.

“We are using a very high level of fire power and artillery,” Israeli military spokesman Brigadier General Motti Almoz said.

In all, 251 Palestinians, most of them civilians, have been killed since the Israel launched the attack on July 8.

Earlier, Turkish Prime Minister Recep Tayyip Erdogan expressed his disappointment over Israel’s air campaign in the Gaza Strip, accusing the Jewish State of seeking a “systematic genocide” of the Palestinians.

“The Western world remains silent, so does the Islamic world. Because those who lost their lives are Palestinian, you can't hear their voices,” Erdogan said.

The outbreak of violence follows the kidnappings and killings of three Israeli teenagers in the West Bank, and the kidnapping and killing of a Palestinian teenager in an apparent revenge attack.