Gaza violence: Pictures show scale of destruction amid threat of Israeli invasion
Watch: Israel masses troops along Gaza as conflict escalates
Israel has massed troops at the Gaza border as tensions and violent clashes with Palestine continue to escalate.
Unrest in recent days has seen rockets fired from Gaza while Israeli forces have bombarded the territory with air strikes, in the most serious fighting since the 50-day war in 2014.
Hamas and other militant groups in Gaza, claiming to be defending Jerusalem, have fired hundreds of rockets at Tel Aviv and other cities.
Israel's response has targeted police and security installations, although the Palestinian authorities said there have been civilian casualties.
Pictures released in the past 48 hours highlight the level of destruction wrought by the escalation of hostilities in the region.
Israel has prepared combat troops along the Gaza border and was in “various stages of preparing ground operations”, a military spokesman said, a move that would recall similar incursions during Israel-Gaza wars in 2014 and 2008-2009.
Benjamin Netanyahu, Israel’s prime minister, has vowed to continue acting to strike at the military capabilities of Hamas – which is regarded as a terrorist group by the UK, US and Israel – and other Gaza groups.
As many as 10 senior Hamas military figures were killed on Wednesday as Israel pressed ahead with a fierce military offensive.
The death toll in Gaza rose to 69 Palestinians, including 16 children and six women, according to the health ministry.
A total of seven people have been killed in Israel, including four on Wednesday.
Watch: More explosions hit Gaza, clashes in the West Bank
Health authorities in Gaza said they were investigating the deaths of several people overnight who they said may have inhaled poisonous gas.
Samples were being examined and they had yet to draw any final conclusions, they said.
With concern growing that the violence that flared on Monday could spiral out of control, the US is sending an envoy, Hady Amr, to the region.
US president Joe Biden said he hoped fighting “will be closing down sooner than later”, while UK minister for Middle East and North Africa James Cleverly said on Thursday morning that Israel has a “legitimate right to defend itself but must do so proportionately”.
Cleverly said Hamas has been firing rockets “indiscriminately” into civilian areas, which he called “completely unacceptable”.
Boris Johnson has also called for restraint on both sides as he urged leaders to “step back from the brink”, adding that the UK is alarmed at the mounting toll of civilian casualties.
Israeli president Reuven Rivlin called for an end to “this madness”.
He said: “We are endangered by rockets that are being launched at our citizens and streets, and we are busying ourselves with a senseless civil war among ourselves.
Israel's domestic unrest has been welcomed by Hamas – with one spokesmen urging Arab citizens to "rise up" against "our enemy and yours”.
Ayman Odeh, a senior Israeli Arab lawmaker, accused Netanyahu's conservative government of inflaming ethnic tensions.
The latest upsurge in violence has been triggered by tensions in Jerusalem during the Muslim holy month of Ramadan, with clashes at a holy site sacred to both Jews and Muslims.
Preparations for Eid al-Fitr, the Muslim holiday marking the end of a month of day-long fasting, have been sombre in Gaza, as residents brace themselves for further devastation and unrest.
Watch: Cameras capture rockets, interceptions between Israel-Gaza