Gaza conflict: Israel calls up 16,000 reserve soldiers
Israel is calling up 16,000 extra reservists to bolster its military as the conflict in Gaza continues.
The move brings the total number of reserves called up by Israel to 86,000. Officials say it will give the army scope to maintain operations.
Separately, Israel has pledged to investigate a strike on a UN-run school that killed at least 16 people.
The UN says it is sheltering 225,178 Palestinians in 86 shelters across Gaza, with 200,000 more displaced.
Most of those others have left their homes and are staying with friends or family.
The total number displaced amounts to 25% of all of Gaza's 1.7 million inhabitants.
Israel began Operation Protective Edge on 8 July. Since then at least 1,360 Palestinians have been killed. Most have been civilians.
Some 58 Israelis have been killed, 56 soldiers and two civilians. A Thai worker in Israel has also died.
More than 100 people in Gaza were killed on Wednesday, Palestinian officials said.
The attack on the school in the Jabaliya refugee camp, which was sheltering more than 3,000 civilians, took place on Wednesday morning.
The US and UN condemned the attack, with UN Secretary General Ban Ki-moon calling it "unjustifiable".
He said "all available evidence" suggested Israeli artillery was the cause.
Spokesman Mark Regev told the BBC Israel would apologise if it discovered that its fire was responsible for the strike on the school.
"We have a policy - we don't target civilians," he said.
"It's not clear to us that it was our fire but we know for a fact there was hostile fire on our people from the vicinity of the school."
Speaking to the BBC's Newsnight, he accused Hamas of hiding weapons in civilian facilities and UN shelters.
Unrwa spokesman Chris Gunness told the BBC that Israel had been told 17 times that the school was housing displaced people, saying the attack caused "universal shame".
He later tweeted that the agency was at "breaking point".
On Wednesday, Israel's security cabinet approved more strikes against Palestinian militant group Hamas, which controls Gaza.
Operations would continue against suspected militants, suspected rocket sites and a network of tunnels discovered leading into Israel, the military said.
At least 19 air strikes were carried out overnight, officials said, while rocket alarm sirens were heard in southern Israel on Thursday morning.
The current conflict, now in its 24th day, is the longest between Israel and militants from Gaza.
A 2012 offensive lasted for eight days, and the 2008 conflict went on for 22 days.
The Gaza Strip, sandwiched between Israel and Egypt, has been a recurring flashpoint in the Israel-Palestinian conflict for years.
Hostilities increased after the abduction and killing of three Israeli teenagers in June. Israel blamed Hamas and carried out a crackdown on the group in the West Bank. Hamas denied being behind the killings.
Tensions rose further after the suspected revenge killing of a Palestinian teenager in Jerusalem on 2 July. Six Jewish suspects were arrested over the youth's abduction and murder.
Recent opinion polls in Israel suggest strong support for the military operation.
Hamas says it will not stop fighting until a blockade, maintained by both Israel and Egypt, is lifted.
Israel occupied Gaza in the 1967 Middle East war and only pulled its troops and settlers out in 2005. Israel considered this the end of the occupation, but it still exercises control over most of Gaza's borders, water and airspace. Egypt controls Gaza's southern border.