Israel-Hamas war: 3 key developments on Wednesday

Days after an unprecedented attack on Israeli border towns by Hamas militants, the grim death toll has continued to rise.

At least 1,200 Israelis were killed in the massacre, which saw areas close to the Gaza border attacked and entire families murdered in their homes, while more than 1,000 people in Gaza have been killed amid ongoing Israeli airstrikes.

With mains power out in Gaza and supplies running low amid Israel's "total siege" of the city, humanitarian groups have called for a de-escalation in the conflict as they struggle to help civilians stuck in a warzone.

Here are the main stories from today:

1. Mains electricity runs out in Gaza

• Gaza has lost mains electricity, after the city's only power station ran out of fuel, Hamas said on Wednesday. The city is currently under "total siege" as Israel attempts to target Hamas militants.

• "Now we are being completely strangled - no electricity, fuel, food or even water allowed in. There are two million people here - how are we supposed to survive without the basic necessities of life?" one Gaza resident told Sky News.

Read more: 'No place is safe' in Gaza as Israel lays siege to Hamas-held enclave (France24)

2. Seventeen British nationals feared missing or feared dead

• Seventeen British nationals are missing or feared dead following the unprecedented attack by Hamas on border towns and at a music festival in Israel.

• Among the 17, three are confirmed to have died in the attacks: Bernard Cowan, who was originally from Glasgow; photographer Dan Darlington; and Corporal Nathan Young, who was serving in the Israeli Defence Forces.

Read more: British nationals feared dead or missing, including children (Sky News)

3. Israeli troops mass at border

• Around 300,000 Israeli troops have gathered at the border with Gaza in what is expected to be an upcoming ground offensive into the city in an attempt to root out Hamas militants.

• As Israeli civilians close to the border with Gaza were evacuated from the area, an Israeli military spokesperson said they were installing “an iron wall” around the city.

Read more: 300,000 Israeli troops assemble at Gaza border to 'execute mission' (Evening Standard)

Where is Gaza?

Gaza, also known as the Gaza Strip, is a densely-populated Palestinian enclave on the eastern coast of the Mediterranean, north-east of the Sinai Peninsula.

Bound by the Mediterranean Sea to the west, Israel to the north and east and Egypt to the south, it is just 25 miles long and six miles wide.

Gaza is one of two Palestinian territories. The other is the Israeli-occupied West Bank.