More than 400 people have been killed by Israeli air strikes on Gaza, according to the Hamas-run health ministry.
The Israeli military said it was carrying out "extensive" strikes after talks to extend the ceasefire failed - it's the biggest wave of strikes since 19 January, when the ceasefire began.
Prime Minister Benjamin Netanyahu's office says Israel will "from now on act against Hamas with increasing military strength", accusing Hamas of "repeated refusal to release our hostages", and of rejecting proposals to extend the ceasefire.
Hamas accuses Israel of attacking "defenceless civilians", and says mediators should hold Israel "fully responsible" for "violating and overturning" the ceasefire.
Israel says 59 hostages are still being held in Gaza, with up to 24 believed to be alive - a group representing hostage families accuses the Israeli government of choosing "to give up the hostages" by launching new strikes.
'Everyone was filled with fear, unsure of where to go'
BBC Arabic's Gaza Lifeline programme has been hearing from Gazans about the fresh wave of Israeli air strikes.
"Everyone was filled with fear, unsure of where to go," a man tells the programme, saying the attack happened as he woke for the pre-dawn Ramadan meal.
Another man, Essam Abu Odeh, says he was suddenly woken by the attack at 02:00 local time.
"My daughter woke me up, warning me about the bombardment. We quickly took shelter against the walls, fearing rubble might fall on us," he recalls.
Mohammed Zaquot, director general of the Gaza Strip's hospitals, says the injured include people with burns and fractures, with many still waiting for surgery.
"The attacks were so sudden that the number of medical staff available was inadequate for the scale of these large strikes, and additional teams were called in immediately to assist," he says.
Verified videos show damage across Gaza after Israeli strikes
BBC Verify has been authenticating video and images being shared on social media after Israeli airstrikes.
We have geolocated material in three locations, although the attacks are reported to have happened across the entire Gaza Strip.
In one clip, which is filmed near Nasser Hospital in Khan Younis in the south, we hear several blasts in the distance.
In another video, a dead or unconscious girl is carried in the arms of a man towards the Indonesian Hospital in northern Gaza.
A third video shows a building in southern Gaza, in the outskirts of Rafah, with smoke coming from part of its upper floor.
A key part of our process is checking the material surfacing on social media is new.
Each of the videos we have verified have had multiple keyframes reverse searched to ensure it is not old footage resurfacing.
