Israel, Australia, Japan, UK, US, others have officially designated Hamas a terrorist organization – European Union has also designated Hamas a terrorist group – October 13, 2023
Apart from the U.S., the U.K., Israel, Australia, Japan and the European Union are among other countries and regional blocs that have officially designated Hamas as a terrorist organization.

>>> U.K. Prime Minister Rishi Sunak said, “The people who support Hamas are fully responsible for this appalling attack. They are not militants. They are not freedom fighters. They are terrorists.” Sunak joined a vigil with local communities at Finchley United Synagogue in London. <<<

Australian Minister for Foreign Affairs Penny Wong gave a speech on Oct. 11 with regard to the attacks on Israel.

"Australia stands against terrorism. We stand in solidarity with Israel. We unequivocally condemn the attack by Hamas: Indiscriminate rocket fire, the targeting of civilians and the taking of hostages. I reiterate Israel’s right to defend itself," she said in her speech via the minister for foreign affairs website.
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Source: Encylopedia Britannica
Israel-Hamas War: war between Israel and Palestinian militants, especially Hamas and the Palestinian Islamic Jihad (PIJ), that began on October 7, 2023, when Hamas launched a land, sea, and air assault on Israel from the Gaza Strip. The October 7 attack resulted in more than 1,200 deaths, primarily Israeli citizens, making it the deadliest day for Israel since its independence.

More than 240 people were taken hostage during the attack. The next day, Israel declared itself in a state of war for the first time since the Yom Kippur War in 1973. The war began with the Israel Defense Forces (IDF) conducting air strikes on the Gaza Strip, followed weeks later by the incursion of ground troops and armored vehicles. By early 2024 tens of thousands of Gazans had been killed and over half of the buildings in the Gaza Strip had been destroyed or damaged.

The October 7, 2023, attack
Aftermath of the October 7, 2023, attack
Survivors of a Hamas rocket strike on Tel Aviv talking with rescuers on October 7, 2023.

On October 7, 2023, Hamas led a stunning coordinated attack, which took place on Shemini Atzeret, a Jewish holiday that closes the autumn thanksgiving festival of Sukkot. Many IDF soldiers were on leave, and the IDF’s attention had been focused on Israel’s northern border rather than on the Gaza Strip in the south.

The assault began about 6:30 am with a barrage of at least 2,200 rockets launched into Israel in just 20 minutes. During that opening salvo, Hamas used more than half the total number of rockets launched from Gaza during all of 2021’s 11-day conflict. The barrage reportedly overwhelmed the Iron Dome system, the highly successful antimissile defense system deployed throughout Israel, although the IDF did not specify how many missiles penetrated the system. As the rockets rained down on Israel, at least 1,500 militants from Hamas and the PIJ infiltrated Israel at dozens of points by using explosives and bulldozers to breach the border, which was heavily fortified with smart technology, fencing, and concrete. They disabled communication networks for several of the Israeli military posts nearby, allowing them to attack those installations and enter civilian neighborhoods undetected. Militants simultaneously breached the maritime border by motorboat near the coastal town of Zikim. Others crossed into Israel on motorized paragliders.

About 1,200 people were killed in the assault, which included families attacked in their homes in kibbutzim and attendees of an outdoor music festival. That number largely comprised Israeli civilians but also included foreign nationals. A March 2024 United Nations report found evidence that some were victims of sexual violence before they were killed. Adding to the trauma was the fact that it was the deadliest day for Jews since the Holocaust.

Hostages taken on October 7, 2023
Portraits of some of the hostages taken during the October 7, 2023, attacks, displayed on a wall during a rally in Tel Aviv calling for their release.

More than 240 others were taken into the Gaza Strip as hostages. Many of them were taken from their homes and some from the music festival. Including Israelis with dual citizenship, more than half of those taken hostage collectively held passports from about two dozen countries, effectively pulling several countries into the efforts to release their citizens.