In both cases, Israel immediately released footage from cameras on unmanned drones showing what are thought to be Hizbollah members emptying both buildings of what appear to be rockets before UN and Lebanese army forces were allowed into the villages to investigate. Monday’s blast was almost identical to an explosion in a Hizbollah commander’s home in Khirbit Selim in July.

Hizbollah’s official statement about Monday night’s explosion in the village of Teir Felsay said unexploded munitions from the 2006 war detonated and wounded a low-level member of the group as he tried to dispose of the material.

Unofficially, however, a representative of the Shiite militant group admitted that an explosion rocked the member’s home, where he was storing military equipment.

The Lebanese military and Hizbollah both deny that anyone was killed in the explosion, but off the record, an official with the military wing of the group said one Hizbollah fighter was killed in the explosion. He would not release the man’s name.

The Hizbollah official, who cannot be identified, said the group believed that the blast was the work of either Israeli commandos or Lebanese agents working on behalf of Israel.

The group strongly suspects someone blew up the arms cache, perhaps by placing a bomb among weaponry.

“We are investigating,” he said. “These two explosions are very suspicious and we believe that they are the work of the Zionists or their Lebanese agents.”

The commander explained that Hizbollah’s refusal to give the Israelis an excuse to invade Lebanon has forced the government of Benjamin Netanyahu, the prime minister, to approve risky operations to expose Hizbollah’s military preparations for another war.

“The resistance has said the next war, and there will be another war, God willing, will not be started by our hands,” he saidd. “So the Zionists are trying to prove we have rearmed and embarrass the UN and Lebanese army by making these actions.”

When asked if the group had rearmed south of the Litani River, which is supposed to provide a buffer between Hizbollah’s military wing and the Israeli border, the official chuckled.

“Did they think we wouldn’t?” he said. “Sayid Hasan Nasrallah himself has said that we have doubled or tripled our supply of rockets since 2006. Do we not have the right to defend our land from aggression?”

The official admitted that Hizbollah had followed the spirit of the 2006 agreement and pulled its hardened military fortifications and operations north of the river, but that the villages remained armed and prepared to repel an Israeli attack.

In 2006, according to Hizbollah sources, Israeli investigations and military analysts, Hizbollah fired about 90 per cent of approximately 4,000 rockets into Israel from about 30 hardened bunker complexes located outside of the southern villages, while part-time fighters and militia defended the villages themselves from Israeli ground troops.

Because of the ceasefire agreement and the presence of the Lebanese army and UN peacekeepers south of the river, Hizbollah appears to have reversed this strategy, pushing its bunkers and professional military wing beyond the river, while bolstering the defences of the villages themselves for the next round of fighting.

The Lebanese army and the UN theoretically have the authority to search villages for weapons, but in practice are more likely to patrol the once heavily defended countryside and avoid altercations with Hizbollah in the villages.

Andrew Macdonald Exum, a military affairs analyst from the Centre for a New American Security in Washington, who has studied the group, said he has seen evidence that Hizbollah is hardening the villages themselves, while pushing much of its static defences out of reach of the peacekeepers.

“I doubt the border defences are as good. You couldn’t move around south Lebanon at all because there was always a guy with an AK-47 to turn you back from closed areas. Today, those guys are in the villages; it would be much easier for the Israelis to avoid Unifil or the Lebanese army and insert special operations soldiers.”

However, Mr Exum said he doubted agents could have pulled off two successful missions without being caught, or whether it would be worth the risk.

mprothero@thenational.ae