Gaza's only power station will run out of fuel today, the Palestinian Energy Authority says.
We've now learnt it could be much sooner - the head of Gaza Energy Authority, Jalal Ismail, says it will stop operating completely today at 14:00 local time (12:00 BST).
Earlier this week, Israel announced a siege of Gaza - cutting its supplies of electricity, fuel, and water.
People in Gaza are seeking shelter in schools and hospitals as Israeli jets attack targets.
The Israeli military says hundreds of thousands of troops are near Gaza "ready to execute the mission we have been given".
The death toll in Israel has reached 1,200 - while more than 1,000 people have been killed by Israeli air strikes on Gaza.
At the other end of the country, Israel has attacked Lebanese territory in response to an an attack from Hezbollah.
And the BBC has learned that 17 UK nationals are dead or missing since Hamas launched its attacks on Saturday.
