By Ruth Sherlock, Jawad Rizkallah, npr.com -- NEAR AARAMTA, SOUTHERN LEBANON — Muscle-bound Hezbollah fighters karate chopped terracotta tiles to smithereens with their bare hands, as others leapt onto fast moving dirt-bikes while wielding rifles. Rockets smashed into a hillside the Lebanese militia had dotted with "enemy" Israeli flags. Snipers hit metal cut-outs of Israeli soldiers from hundreds of meters away. "Oh Zionists, we are coming for you, from places you know and places you don't," a Hezbollah member shouted into a microphone, as fighters sprayed their targets with live ammunition in the simulated attack. "We will come at you from the sea, from the air and from the land."

The military exercise on Sunday at a Hezbollah base in southern Lebanon, close to the border with Israel, was the biggest public show of force by the militia in at least a decade. The group invited local and foreign journalists to attend, giving them rare access to a sensitive military position to report on the event. The display was ostensibly to mark the upcoming anniversary of the withdrawal of Israeli forces from southern Lebanon on May 25, 2000. But it also comes at a time of heightened tension between Israel, Hezbollah and allied groups.

Last month saw the biggest escalation of violence on the Lebanese-Israeli border since the 2006 war between Israel and Hezbollah. Following Israeli raids on worshipers in the Al Aqsa mosque, dozens of rockets were fired into Israel from southern Lebanon. Israel responded with limited airstrikes in the south of the country. Although Hezbollah did not claim responsibility for the attack — and Palestinian militias operate in this part of Lebanon — experts believe an attack on this scale would not have happened without the group's consent. The military exercise also follows a closing of ranks between Hezbollah, Hamas, Islamic Jihad and other Palestinian organizations. Ismail Haniyeh, the head of Hamas' political bureau, was in Beirut during the rocket attacks on April 6. He met Hezbollah's leader, Hassan Nasrallah, to discuss "the readiness of the Axis of Resistance" against Israel, according to a statement by the Lebanese militia.

While Hezbollah periodically fired rockets into the Golan Heights from neighboring Syria, during the war there, it has become cautious about launching attacks from Lebanon. As well as being an armed militia group sponsored by Iran, Hezbollah is now also a major force in Lebanese politics, and has in recent years avoided inviting Israeli attacks on the country. "Hezbollah try to needle the Israelis from time to time, but they're very risk averse," said Nicholas Blanford, a Lebanon-based expert on the group affiliated with the Atlantic Council. The simulated exercises are a lower risk way for Hezbollah to remind Lebanese of its military prowess. "It's also a means of rallying the support base, specifically the Shia community," said Blanford. "It may also be sending subtle messages to Hezbollah's opponents in Lebanon that we are here, we're still a powerful force."

At its military base in the south of the country on Sunday, the militia welcomed guests with a brass band. Drones held the Lebanese flag and Hezbollah's distinctive yellow banner suspended overhead. Invitees walked past masked men in military uniforms standing on trucks equipped with rocket launchers, before being seated beside the parade ground. For more than an hour and a half, members of the group showed off their skills — one point they jumping through flaming metal hoops, and engaging in hand-to-hand combat. They detonated explosions on a nearby hill during a simulated attack on an Israeli settlement. Rockets fired from drones blew up Israeli flags, as, amid the live gunfire and plumes of smoke, a group of fighters drove to the hilltop and victoriously planted the Hezbollah flag.

In a speech after the exercise, Hashem Safieddine, the head of the group's executive council, said the show was intended to "solidify the balance of deterrence" with Israel. Speaking directly to Israeli leaders, he said that faced with any escalation, Hezbollah was ready to respond. "We will cause a very black day of the kind you never imagined."