Israeli commando units have made brief incursions into Lebanese territory in recent days to prepare for a possible wider invasion targeting Hezbollah, although no decision has yet been made about whether or when to begin one, officials said.

The raids — confirmed by six Israeli officers and officials, and one Western official — have focused on gathering intelligence about Hezbollah positions close to Israel’s northern border, as well as on identifying Hezbollah tunnels and military infrastructure in preparation to attack them from the air or the ground.

The officials all spoke on the condition of anonymity to discuss a sensitive military matter. The incursions follow months of similar covert missions in which Israeli special forces briefly crossed the Lebanon border for reconnaissance, but have increased in intensity in recent days as commanders prepared for a wider maneuver, three of the officials said.

Yoav Gallant, Israel’s defense minister, continued the drumbeat of officials hinting that Israel could send ground troops into Lebanon. “We will mobilize all our capabilities,” he told an armored tank brigade in a video released by his office on Monday. “If someone on the other side misunderstood that, that means all our capabilities, and you’re part of this effort.”

The preparations come as Israel carries out a far-reaching string of attacks across the Middle East aimed at Iranian-backed militias including Hamas, Hezbollah and the Houthis in Yemen.

Here’s what else to know:

• Hamas official killed: Hamas said on Monday that its leader in Lebanon, Fatah Sherif, had been killed with his family in an airstrike on a refugee camp for Palestinians in southern Lebanon. The Israeli military said he had coordinated Hamas’s ties with Hezbollah. The main United Nations agency for Palestinian refugees, UNRWA, said on Monday that Mr. Sharif had been an employee of the agency but had been placed on leave in March after it received allegations “about his political activities.”

• Hezbollah’s future: Sheikh Naim Qassem, the deputy secretary general of Hezbollah, said in a televised address on Monday that the group would name a leader to replace Hassan Nasrallah “at the closest opportunity.” Israel killed Mr. Nasrallah on Friday in a bombardment in a densely populated neighborhood near Beirut, and launched dozens more attacks on Hezbollah targets on Sunday, targeting rocket launchers and buildings that Israel said the militia had used to store weapons.

• Beirut strike: Israel said it was behind a blast in Beirut that hit a residential building overnight. The Popular Front for the Liberation of Palestine, a militant group based in Lebanon and Gaza, said that three of its members had been killed in the blast, in the largely Sunni Muslim neighborhood of Cola. The group is mostly known for a string of airline hijackings and bombings decades ago. It was the first known Israeli attack in central Beirut since Israel and Hezbollah fought a war in 2006.

• Yemen: Israeli warplanes attacked power plants and shipping infrastructure on Sunday in Yemen, where the Iran-backed Houthi militia has been conducting attacks against Israel and menacing trade in the Red Sea. The Houthis have been acting in solidarity with Hamas, the Iran-backed group fighting Israel in the Gaza Strip.

• Gaza: An Israeli strike in northern Gaza on Sunday killed at least four Palestinians and wounded several others, according to the Palestinian civil defense. The Israeli military said it had struck Hamas militants who were using a school-turned-shelter as a command and control center.