A US intelligence source confirmed to ABC News that Israel had a hand in manufacturing the pagers that exploded on Hezbollah operatives this week, with this type of "supply chain denial" operation being planned for at least 15 years.

The CIA had long been reluctant to use the tactic because the risk to innocent people was too high, the source said.

The source confirmed to ABC News on Friday that the planning for the attack involved front companies, with multiple layers of Israeli intelligence officers and their assets posing as a legitimate company that produced the pagers, with at least some of those who did the work unaware of who they were actually working for.

The New York Times was the first to report Israel's involvement in the manufacturing.

According to sources, one to two ounces of explosives and a remote trigger to start the explosion were planted in the pagers.

The explosions that occurred in Lebanon over the past two days, which were detonated remotely using explosives inside pagers or wireless communication devices, resulted in the death of at least 37 people and the injury of 2,931 others, according to the Lebanese Minister of Health, Firas Al-Abyad.

The conflict between Hezbollah and Israel expanded on Thursday, as Israel launched strikes on Lebanon and Hezbollah responded with gunfire.

ABC News reached out to BAC Consulting — the Hungary-based company contracted to produce the pagers on behalf of Gold Apollo in Taiwan — but neither company responded to our repeated requests.

A Hungarian government spokesman told ABC News on Wednesday that the pagers were never in Hungary and that the company was "a commercial intermediary, with no manufacturing or operating location in Hungary."

In a speech on Thursday, Hezbollah leader Hassan Nasrallah said the group’s top leadership had old pagers, not the new ones used in the attack, which were reportedly shipped in the past six months. The group has launched a full investigation into the explosions.

"Not all pagers have been distributed and some have been turned off," Nasrallah said.

He added, "The enemy wanted to kill at least 5,000 people within two days... and the enemy knew that the number of pagers reached 4,000."

Israel launched an air strike on the southern suburbs of the Lebanese capital Beirut on Friday, targeting Hezbollah military commander Ibrahim Aqil.

Hezbollah said in a statement that Hajj Abdul Qader joined the procession of his brothers, the great martyr leaders, "after a life full of jihad, work, wounds, sacrifices, dangers, challenges, achievements, and victories."

The statement pointed out that Jerusalem was always in the martyr’s heart, mind, and thoughts day and night, and “was the passion of his soul, and praying in its mosque was his greatest dream.”

He added: "We offer our condolences and congratulations to all the mujahideen and resistance fighters in all arenas, and to the loyal and faithful resistance crowd, on the martyrdom of the great jihadist leader and a group of his martyred brothers. We especially extend our condolences to their honorable families, each and every one of them."

Two security sources told Reuters that a prominent leader in the group, Ibrahim Aqil, was killed in an Israeli strike on the southern suburb, while one of the sources confirmed that Aqil was killed alongside members of the party's "Radwan" unit while they were holding a meeting.

According to Lebanese media reports, Ibrahim Aqil took over the duties of Fouad Shukr, who was recently assassinated by Israel. The Israeli Channel 13 described Aqil as “the number 3 figure in Hezbollah, who recently became number 2.”

The Israeli occupation army claims that "Aqil has been working since 2004 as the head of the operations and activities of Hezbollah elements in the fields of sabotage, anti-tank missiles, explosive devices, air defense, and other military fields."

Akil, who was born in Bednayel in the town of Younin in Lebanon, and is also known as “Tahseen,” is considered a member of Hezbollah’s highest military body, the Jihad Council, according to the US State Department.

The US State Department, through the Rewards for Justice (RFJ) program, offered a reward of up to $7 million for information on Hezbollah leader Ibrahim Akil.

For his part, US President Joe Biden confirmed on Friday that he is "working" to allow residents to return to their homes in the border areas of southern Lebanon and northern Israel, in his first comment on the escalating tension between Israel and Hezbollah.

Biden told reporters at the start of the meeting that he wanted to “make sure that people in northern Israel as well as southern Lebanon are able to get back home, get back safely,” stressing that “the secretary of state, the secretary of defense, our entire team are working with the intelligence community to try to get that done. We will continue to work until we get it done, but we have a long way to go.”

The army said in a statement, "Earlier today, warplanes carried out a precise raid in the Beirut area, under the guidance of the Military Intelligence Service, and eliminated Ibrahim Aqil, the head of Hezbollah's operations system and the actual commander of Hezbollah's Radwan Force." It added, "In the raid, Aqil and senior leaders in the command of the operations system and the Radwan Force were eliminated."

Shortly after the strike, an Israeli official said that Prime Minister Benjamin Netanyahu had postponed his departure to the United States by one day, to September 25, due to the security situation on the northern front with Lebanon.