Israel responds after Palestinian Islamist group launches surprise attack and incursion

• Israel declares state of war after Hamas launches surprise attack – live updates

The Palestinian Islamist group Hamas has launched a surprise attack on Israel, its biggest in years.

Here is what we know so far:

Hamas militants entered Israeli territory in the early hours of Saturday morning, appearing to take control of various communities in the south of the country. Fighting is still going on in some areas.

Hamas fired thousands of rockets towards Israel, according to Israeli authorities. The Hamas military commander, Mohammed Deif, said 5,000 had been fired, but an Israeli military spokesperson said 2,500 had been fired.

The death toll in Israel is at least 40, according to the Israeli national rescue service. The country’s health ministry said at least 561 wounded were being treated in hospital, according to an Associated Press count based on public statements and calls to hospitals.

The Palestinian health ministry says at least 198 people have been killed and 1,610 wounded in Gaza by Israeli retaliation after the Hamas attack.

There are reports of Israeli hostages in Gaza.

“We are at war and we will win it,” the Israeli prime minister, Benjamin Netanyahu, said in a video address to the country.

The British prime minister, Rishi Sunak, said he was “shocked by this morning’s attacks by Hamas terrorists against Israeli citizens”. “Israel has an absolute right to defend itself,” he said.

Adrienne Watson, the spokesperson for the US national security council, said: “The US unequivocally condemns the unprovoked attacks by Hamas terrorists against Israeli civilians. We stand firmly with the government and people of Israel and extend our condolences for the Israeli lives lost in these attacks.”

Saudi Arabia, which has been in talks with the US about normalising relations with Israel, called on both sides to exercise restraint.

Many areas are still without water and electricity following three days of Israeli airstrikes

In Shujaiya, a neighbourhood of Gaza City already scarred by several rounds of war, men passed around coffee and dates under the shade of a colourful mourning tent while Palestinian Islamic Jihad battle songs blared from sound systems.

About a dozen men carrying AK-47s, their faces shielded by black balaclavas, lined the entrance to the tent, and the militant group’s black and yellow flag flew overhead.

Health authorities in Palestinian enclave report 15 dead in Israeli attacks targeting Islamic Jihad

Residents of the Gaza Strip were bracing for the possibility of a new round of war on Saturday after two days of “pre-emptive” Israeli airstrikes against a Palestinian militant group.

Israeli warplanes hit several sites in the blockaded territory on Friday, part of a surprise operation named “Breaking Dawn” that the Israel Defence Forces (IDF) said thwarted alleged planned rocket attacks by Palestinian Islamic Jihad.

Palestinian officials say at least 10 dead after Israel said it was preparing to ‘remove the threat from this region’

Israeli warplanes struck numerous sites in the Gaza Strip on Friday in what Israel said was a preemptive strike against Palestinian factions allegedly planning rocket strikes at targets in Israel.

Palestinian health officials reported that at least 10 people died and 55 were wounded in an initial barrage which killed the commander of Islamic Jihad, Tayseer Jabari, in the north of Gaza. Among the fatalities was an eight-year-old girl.

Hisham al-Sayed seen lying in bed wearing a mask, with what appears to be an oxygen canister next to him

Gaza’s Hamas rulers have released a video of a captive Israeli citizen held incommunicado since 2015, showing the man lying in a hospital bed wearing an oxygen mask.

It was the first image of Hisham al-Sayed to be released since he wandered across the frontier from southern Israel into Gaza. Its release came a day after Hamas said the condition of one of the Israelis it was holding captive had deteriorated.

Israeli media estimated around 25,000 people took part in contentious annual flag march through Muslim parts of Ohld City

Thousands of Israeli religious nationalists have paraded through Muslim parts of the Old City of Jerusalem, putting the city on edge after violence during the same event last year helped spark an 11-day-war between Israel and Hamas, the Palestinian militant group in the Gaza Strip.

The annual flag march, in which Israelis enter the highly symbolic Damascus Gate and walk through the Muslim Quarter to the Western Wall waving the national flag, takes place around sunset on what Israel calls Jerusalem Day, the celebration of the capture and annexation of East Jerusalem in the 1967 war, a move that is not internationally recognised.

Omar Abu al-Ouf’s father, mother, brother and sister were all killed in the attack on their apartment building last May

Omar Abu al-Ouf is revising for his final school exams, hoping to do well enough to pursue his dream of becoming an engineer, but it’s difficult for the 17-year-old to focus. His mind constantly drifts to his family, all of whom died last year when an Israeli airstrike destroyed their apartment building in a middle-class neighbourhood of Gaza city.

“It’s like he goes somewhere else,” said his grandmother, Manar, in the living room of the boy’s uncle’s house, where he now lives. “His whole family is gone, for nothing.”

Latest court order raises hopes of verdict in trial of World Vision’s Mohammed El Halabi

Pressure is mounting on Israel to conclude the trial of a Gazan aid worker accused of funnelling relief money to Hamas in a six-year-old case widely derided by the international community as “not worthy of a democratic state”.

Mohammed El Halabi, the head of the US-based charity World Vision’s Gaza office, was detained in 2016 after being accused by Israel’s Shin Bet security service of transferring $7.2m (£5.4m) a year to the Palestinian militant group in control of the Gaza Strip.

Cross-border gunfire earlier on Saturday seriously injured an Israeli soldier and wounded 41 Palestinians

Israeli aircraft struck Hamas sites in Gaza late on Saturday, the military said, in an escalation of hostilities after earlier cross-border gunfire seriously injured an Israeli soldier and wounded 41 Palestinians, including two critically.

The injuries came during a Gaza protest organised by the enclave’s Islamist rulers, Hamas, and other factions in support of Jerusalem, where Palestinian clashes with Israeli police helped spark an 11-day Israel-Hamas conflict in May.