This story was updated at 2:48 p.m.
A small-scale attack from Lebanon was widely anticipated given the escalation between Israel and Hamas in recent days, but it is unlikely that the Lebanon-Israel front will deteriorate further. Shiite militant group Hezbollah, the most powerful military force in Lebanon, is deeply engaged in Syria’s grueling civil war on behalf of the regime and does not want to open a front with Israel.
Israel appears to see the attack as an isolated incident that doesn't merit an escalation along its northern border– the shells it fired in response targeted an unpopulated forested hillside between two villages.
The rocket, a 107mm Grad, was launched from an olive grove five miles north of the border, near the village of Mari, and exploded in an open area near Kfar Yuval a few hundred yards inside Israel. There were no reports of casualties or damage.
The Lebanese army said that three rockets were fired – one struck Israel and a second exploded at the launch site. The army reportedly found bloodstains and a ripped shoe, suggesting that one of the perpetrators was injured in the premature explosion. The whereabouts of the third rocket remains unclear. Israel said only rocket landed on its territory, while the Lebanese army said it had defused two rockets that had been set for firing.
On Friday evening, Lebanese news reports said a man from a nearby Sunni village was arrested after confessing that he had launched the rockets with two Palestinian accomplices. News reports said that the suspect was a member of an "extremist group," a term that usually refers to Al Qaeda-inspired factions rather than Hezbollah.
Israeli Lt. Col. Peter Lerner told the Associated Press that militants in Lebanon may seek to join the conflict between Hamas and Israel but it was still unclear whether the rocket fire from Lebanon was “symbolic or something more substantial."
Lebanese parliamentarians condemned Israel’s artillery fire into south Lebanon and questioned the motives behind the rocket launch.
“This cannot be described as a resistance act because it served Israel, which is seeking to draw attention away from the massacres it is committing against the Palestinians in Gaza,” said Mohammed Safadi, a lawmaker from Tripoli in northern Lebanon.
The Lebanon-Israel border has been generally calm since the end of the month-long war in 2006 between Israel and Hezbollah, the eighth anniversary of which falls on Saturday. Friday’s rocket attack was the sixth to strike Israel since the 2006 war. Four other attempts were either thwarted or exploded inside Lebanon.
These isolated rocket attacks usually go unclaimed. However, the Sunni jihadist group Abdullah al-Azzam Brigades took responsibility last August for firing four extended-range 122mm Grad rockets over the border. Two of the rockets hit Israel, a third fell into the Mediterranean Sea, and a fourth was intercepted by Israel’s Iron Dome missile defense system.
Lebanese and foreign security sources have expressed concern that Sunni militants could seek to destabilize the border area in order to provoke a clash between the Iranian-backed Hezbollah and Israel. The Abdullah al-Azzam Brigades has claimed responsibility for a number of anti-Hezbollah attacks in the past year. These include twin suicide car bombings against the Iranian embassy in Beirut in November and the Iranian cultural center in February, as well as a rocket attack against Shiite villages in the Bekaa Valley in January and a roadside bomb ambush against a Hezbollah vehicle in July 2013.
On July 1, Sheikh Sirajeddine Zouraykat, spokesman for the Abdullah al-Azzam Brigades, warned Hezbollah that it would face further attacks unless it pulled its fighters out of Syria.
“I tell Iran's party [Hezbollah] to quickly withdraw from Syria before it is too late,” he wrote on his official Twitter account.