Sunday’s strikes represent a major increase in intensity on the Israel-Lebanon border that risks slipping beyond tit-for-tat retaliation, says Yossi Mekelberg, an associate fellow with the Middle East and North Africa Programme at Chatham House, a London-based international affairs think tank.

“We are on the cusp of something that could be quite dangerous,” he told NBC News, noting that it was the most intense exchange of fire since the 2006 war between Israel and Hezbollah.

“What happens if Israel’s defense system doesn’t work? Or one or two missiles hit a block of flats? By hitting this or that, they provoke each other to retaliate. These are fine margins keeping people awake at night.”

Hezbollah said Sunday morning that it had completed military operations for the day, but Mekelberg said the conflict could continue to escalate in the coming days. 

“It means Monday is going to be a different story, right?”

Video shows what appear to be rockets being intercepted in Haifa, Israel, as the country exchanged fire before dawn local time with Hezbollah militants in Lebanon.

Cease-fire negotiations that could bring an end to the fighting in Gaza are set to continue in Cairo this week, and there are concerns that the latest escalation between Israel and Hezbollah could stifle an elusive deal.

But H.A. Hellyer, a scholar at the Carnegie Endowment for International Peace in Washington D.C., believes the cease-fire negotiations were “already in pieces.”

“I’m not convinced that this morning’s attacks will have much of an impact on the ceasefire negotiations,” he told NBC News. “I don’t think those negotiations were really going anywhere anyway.”

But Hellyer added that Israel’s strikes on Lebanon demonstrate that Israeli Prime Minister Benjamin Netanyahu was not interested in de-escalating the situation.

“The overall trend here is one of escalation unless you actively try to avoid it,” he added. “And I don’t think that Netanyahu’s actively trying to avoid it at all, it’s been stated many times over recent weeks and months that the Israelis want to reset relations on the border, and they’ve been beating the drum when it comes to Hezbollah.”

The Israel Defense Forces lifted restrictions in some areas on Sunday afternoon following the latest round of strikes between Israel and Hezbollah.

The move follows a "situational assessment" and a decision to make changes to the nation's Home Front Command’s defensive guidelines.

The IDF statement read: "As part of the changes, it was decided that restrictions will be lifted in the areas of the Upper Galilee, specified communities in the southern Golan, the Lower Galilee, the Central Galilee, the Beit She’an Valley, the Valleys, the Haifa Bay, the Carmel, Wadi Ara, Menashe, Sharon, and Dan."

The statement also said that "partial activity" will be permitted in the northern Golan and specified communities in the southern Golan."

In a briefing earlier today, Lt. Col. Nadav Shoshani a spokesperson for the Israel Defense Forces, provided updates on the impacts of Hezbollah's strikes on Israel, in response to a question from the New York Times.

"We're still in a situation of the aftermath of the attack," he said, but that there was, "very little damage."

Egypt's foreign ministry has warned of the dangers of the region "slipping into a state of comprehensive instability" following Sunday morning's strikes between Israel and Hezbollah, calling the developments "dangerous and rapid."

The statement went on to stress the importance of "preserving Lebanon's stability," and reaffirmed its support for a "comprehensive cease-fire and end end to the ongoing war in the Gaza Strip."

Cease-fire negotiations that seek to bring an end to the current conflict between Israel and Hamas are set to take place in the Egyptian capital Cairo this weekend.

This video, verified by NBC News, shows the moment a UAV is intercepted by the Israeli air force over northern Israel.

Formed in the early 1980s as Lebanon was wracked by a civil war, Hezbollah, sometimes spelled Hizballah or Hezbullah, is a Shia political party and militant organization. The name means “Party of God.”

Created with support from Iran, the group set a mission to expel Israeli forces from Lebanon, while resisting Western influence in the Middle East.

The organization brands itself as a Shia resistance movement within Lebanon that believes in the country’s right to self-determination, while also pledging its allegiance to Iranian Supreme Leader Ali Khamenei, according to a recent report by the Council on Foreign Relations, a New York based think tank.

Hezbollah’s current leader, Hassan Nasrallah, was a member of the Amal Movement, a Shia militia that was one of the many groups vying for power during the Lebanese civil war, before he joined Hezbollah in 1982.

The group’s militant activity and support from Tehran has led the U.S., the United Kingdom and other nations to designate it as a terror organization.

But Hezbollah also has lawmakers sitting in the Lebanese parliament and provides numerous social services within the country.

You can read more about Hezbollah and its fraught relationship with Israel here.

The latest strikes between Israel and Hezbollah could "easily spiral out of control" and risk triggering "all-out war," says Fawaz Gerges, Professor of International Relations at the London School of Economics.

"These morning attacks mark a turning in their scale and gravity," he told NBC News.

"The core concern is that if the ongoing ceasefire talks in Cairo and Doha fail to end the war in Gaza, the risks of a wider regional conflict will increase considerably."

Gerges added that a cease-fire between Israel and Hamas could end the escalation on the Israel-Lebanese border, while also putting an end to Houthi rebel attacks in the Red Sea.

"It all depends on the cease-fire negotiations," he said.