Israeli security forces late Wednesday released a ship believed to have been carrying tons of weapons from Iran to Hezbollah, which it seized early Wednesday in Mediterranean waters, and allowed the ship to continue on its originally planned route.

The ship was set to continue to Turkey and then to Egypt. Israel completed unloading the cargo on Thursday morning and decided that the crew manning the vessel had no connection to the weapons found on board.

The Lebanon-based Hezbollah militant group on Thursday denied any connection to the 500 tons of weapons seized by Israeli commandos during a raid on the ship.

"Hezbollah denies any link to the weapons that the Zionist enemy claims it removed from the vessel Francop," the group said in a statement. "At the same time it condemns Israeli piracy in international waters."

The Hezbollah response came after Syrian Foreign Minister Walid Moallem said reports that Iran had shipped weapons to Hezbollah were fabricated.

Israel's Foreign Ministry, meanwhile, invited foreign ambassadors to the Ashdod port to view the tons of seized weapons.

The Francop was captured by Israel Navy missile boats and naval commandos before dawn Wednesday in an operation dubbed Operation Four Species.

The arms shipment began its journey about 10 days ago aboard an Iranian ship that sailed from the port of Bandar Abbas to the Mediterranean port of Damietta (Dumyat) in Egypt. The cargo - which, according to a ship manifest, was destined for Syria - was unloaded in Egypt, and then loaded three days later onto the Francop, a German-owned ship operated by a Cypriot company. The ship's crew reportedly did not know what the containers really held.

The navy, which tracks suspicious activity at sea along known smuggling routes in the Mediterranean and the Red Sea, located the Francop shortly after it left Damietta on Tuesday on its way to Limassol, Cyprus, and thence to Syria. Toward evening, an Israeli navy missile boat made contact with the Francop and asked to conduct a routine inspection of its cargo. Israeli naval commandos boarded at around midnight on Tuesday, in rough seas, and met with no resistance from the ship's crew of 11.

The Israeli naval personnel checked the ship's manifest, which showed that the cargo was going to the Syrian port of Latakia, and began opening the containers. They found sacks of polyethylene near the opening and along the walls of the containers, but behind the sacks, they discovered numerous crates of ammunition and artillery shells. At that point, they ordered the crew to sail to Ashdod.

Upon the ship's arrival at the Israeli port, the lengthy process of unloading the cargo began. It was expected to be completed on Thursday morning.

The cargo included thousands of medium-range 107- and 122-millimeter rockets, armor-piercing artillery, hand grenades and ammunition for Kalashnikov rifles. Even with all the cargo not yet unloaded, the navy estimated that the haul included more than 3,000 rockets and a total of 300 tons of weaponry. This compares to only 40 tons seized in 2002 on the Karine A, whose weapons were destined for the Palestinians.

The rockets and artillery shells on the Francop were mostly manufactured over the past two years, and though they had English-language markings, intelligence officials believe that most were manufactured in Iran ¬ other than the 122-millimeter rockets, which are apparently of Russian manufacture.

Because of the manner in which the crates were hidden, the army is convinced that the weapons were destined for Hezbollah in Lebanon. Such a shipment would be a clear violation of UN Resolution 1701, which ended the Second Lebanon War in 2006.

The cargo did not include rocket launchers or advanced weaponry that would alter the balance of power with Israel. Nonetheless, the army said, the rockets that were seized are the equivalent of about 10 percent of Hezbollah's existing stock, and could have been used for weeks of intensive shelling of northern Israel.