Israeli prime minister Benjamin Netanyahu has warned the country is prepared to "significantly expand" its operation in Gaza as "Operation Pillar of Defence" enters its fifth day.
Shelling in Gaza has killed six people today and in Gaza two media buildings were hit with eight Palestinian journalists hurt - leading Israel's president Shimon Peres to deny they were targeting journalists.
Speaking to sky News on Sunday morning, Peres says Israel made "supreme efforts" to avoid hitting civilians.
"Unfortunately, they [Hamas] use their bombs in their mosques to hide their arms, to make them headquarters of shooting. In spite of it, until now I believe almost no civilians were hit.
"We have bombed headquarters where they host journalists as well, it is very hard for us to know, but journalists are not our targets."
According to estimates 52 Palestinians have been killed and more than 400 civilians wounded since Wednesday. Three Israeli civilians were killed earlier in the week and more than 50 have been wounded.
The BBC reports hospitals in Gaza are "struggling" to cope with the numbers of injured people.
Some have criticised Israel for what they see as a disproportionate response to largely ineffective rocket attacks, with Prime Minister Eli Yishai doing nothing to quell their anger.
On Saturday night it was reported by Haaretz that Yishai said the conflict's purpose was "to send Gaza back to the Middle Ages" to make Israel "calm".
During a cabinet meeting on Sunday, Netanyahu said Israel was "exacting a heavy price from Hamas and the terrorist organisations and the Israel Defence Forces are prepared for a significant expansion of the operation," reports Reuters.
The UK's foreign secretary William Hague warned on Sunday that Israel risks losing international sympathy if it launches a ground invasion in Gaza in a bid to crack down on militants.
Hague said Hamas bears "principal responsibility" for sparking the current conflict in Gaza, after firing rockets into southern Israel.
Israel's largest city, Tel Aviv, and the holy city of Jerusalem have both been targeted by rockets.
Hague accused Iran of playing a key role in supplying Hamas militants with arms and the rockets which sparked the current crisis.
And he said it was vital to look beyond the "hour to hour" developments on the ground and seek a solution to the wider regional issues.
David Cameron has urged Israel to "do everything possible" to end the crisis in Gaza as its military continued to trade missile strikes with Hamas amid fears of a new ground war.
Barack Obama has said America is "fully supportive of Israel's right to defend itself".