DEIR AL-BALAH, Gaza Strip — An Israeli strike early on a mosque in the Gaza Strip killed at least 19 people, Palestinian officials said, as Israel intensified its bombardment of northern Gaza and southern Lebanon in a widening war with Iran-allied militant groups across the region.

New strikes began in the Beirut suburbs late Sunday, AP video showed, and Hezbollah claimed an attack on Haifa, Israel.

Israel also has been battling Hamas since the group’s Oct. 7, 2023, attack on Israel and has opened a new front in Lebanon against Hezbollah, which has traded fire with Israel along the border since the war in Gaza began. Israel has vowed to strike Iran itself after Tehran launched a ballistic missile attack last week on Israel, and Iran’s state media said some flights would be halted overnight until 6 a.m. Monday, citing “operational restrictions.”

Israel and Hezbollah have traded fire across the Lebanon border almost daily since the day after Hamas’ cross-border attack, which killed 1,200 Israelis and took 250 others hostage. Hamas still holds around 100 captives, a third of whom are believed to be dead. Israel declared war on Hamas in the Gaza Strip in response to the attack. As the Israel-Hamas war reaches the one-year mark, nearly 42,000 Palestinians have been killed in Gaza.

And as Israel prepares for a day of somber memorials marking the anniversary, the military said it was increasing troop presence in Israel’s south to protect memorials held along the Gaza border.

Rallies continue around the world marking the anniversary. A large memorial planned by bereaved families was expected to draw a crowd of more than 40,000 in Tel Aviv.

Overall, the widening conflict risks further drawing in the United States, which has provided military and diplomatic support to Israel. Iran-allied militant groups in Syria, Iraq and Yemen have joined in with strikes on Israel.

A stabbing and shooting attack at the central bus station in the southern Israel city of Beersheba left one person dead and 10 wounded, according to first responders. Police said the woman killed was a border police officer. They did not identify the assailant but said they were treating it as a terror attack.

The strike Sunday by Israel hit a mosque where displaced people sheltered near the main hospital in the central Gaza town of Deir al-Balah. An additional four were killed in a strike on a school-turned-shelter near the town. The Israeli military said both strikes targeted militants, without providing evidence.

An Associated Press journalist counted the bodies at the Al-Aqsa Martyrs Hospital morgue. Hospital records showed that those killed at the mosque were all men.

The Israeli military announced a new air and ground offensive in Jabaliya, in northern Gaza, home to a refugee camp dating to the 1948 war surrounding Israel’s creation. Israel has carried out several large operations there during the past year, only to see militants regroup.

The military said three soldiers were severely wounded in Sunday’s fighting in northern Gaza.

Israel reiterated its call, from the early weeks of the war, for the complete evacuation of northern Gaza. Up to 300,000 people are estimated to have remained in the heavily destroyed north while around a million fled to the south.

“We are in a new phase of the war,” the military said in leaflets dropped over the area. “These areas are considered dangerous combat zones.” A later statement said three projectiles were identified crossing from northern Gaza into Israeli territory, with no injuries reported.

Residents fled again. “Since Oct. 7 to the present day, this is the 12th time that I and my children, eight individuals, have been homeless and thrown into the streets and do not know where to go,” said one, Samia Khader.

Palestinians reported heavy Israeli strikes. The Civil Defense, first responders with the Hamas-run government, said it recovered three bodies, including a woman and a child, after a strike hit a home in the Shati refugee camp.

Residents mourned relatives. Imad Alarabid said on Facebook that an airstrike on his Jabaliya home killed a dozen family members, including his parents. Saeed Abu Elaish, a Health Ministry medic, said he was wounded.

“Pray for us,” he wrote on Facebook.

Hassan Hamd, a freelance TV journalist whose footage had aired on Al Jazeera, was killed in shelling on his home in Jabaliya. Anas al-Sharif, an Al Jazeera reporter in northern Gaza, confirmed his death.

Israel’s military says it has expanded the so-called humanitarian zone in southern Gaza. Hundreds of thousands have sought refuge in sprawling tent camps there with little food, water or toilets. Israel has carried out strikes in the zone against what it says are militants hiding among civilians.

In Beirut, airstrikes lit up the skyline and explosions echoed across the southern suburbs, known as the Dahiyeh, overnight as Israel struck what it said were Hezbollah militant sites.

Resident Maxime Jawad called it “a night of terror.”

Israeli Prime Minister Benjamin Netanyahu visited a military base near the border Sunday and called soldiers “the generation of victory.”

On Sunday, French President Emmanuel Macron reiterated his call for a partial arms embargo on Israel — a demand that prompted an angry response from Netanyahu. Macron’s office said he favors a halt to arms exports for use in Gaza because a cease-fire is needed to stop the violence and “clear the way to the political solutions needed for the security of Israel and the whole Middle East.”