JERUSALEM: Israeli commandos seized a ship Wednesday that defense officials said was carrying hundreds of tons of weapons bound for Lebanon’s Iranian-backed Hezbollah movement — the largest arms shipment Israel has ever commandeered.

The Israeli military said an Iranian document was found on board, showing that the arms shipment originated from Iran, although the paper was not shown to reporters.

“It’s a cargo certificate that shows that it was from a port in Iran,” military spokeswoman Lt. Col. Avital Leibovich said. “All the cargo certificates are stamped at the ports of origin, and this one was stamped at an Iranian port.”

The Israelis boarded the ship before dawn in the waters near Cyprus. Israel has long accused Iran of arming its enemies.

Rear Adm. Roni Ben-Yehuda, the deputy Israeli navy commander, told a briefing that “hundreds of tons” of weapons were found on the ship, giving a much higher estimate than an earlier one of more than 60 tons.

Ben-Yehuda added the weapons were “a drop in the ocean” of arms being shipped to Hezbollah. But hours after the seizure, Israel had not provided proof that the arms were meant for the Lebanese militants.

In the southern port Israeli city of Ashdod where the ship was towed and docked, hundreds of rockets and piles of boxes of grenades were stacked on the shore as Israeli forces unloaded the cargo, a process that was expected to take hours.

Wednesday’s seizure was bigger than a similar haul in 2002, when Israeli military confiscated a vessel with 50 tons of missiles, mortars, rifles and ammunition headed for Hamas militants in the Gaza Strip.

Ben-Yehuda said weapons, including Katyusha rockets, were stashed on a commercial vessel operating under the guise of an aid ship, captained by a Pole and flying an Antiguan flag.

Based on intelligence reports, a naval unit patrolling the area intercepted and boarded the vessel without incident, defense officials said.

Deputy Defense Minister Matan Vilnai said the crew was not aware of the cargo’s contents. The ship, the Francop, is operated by United Feeder Services, a Cyprus-based shipping company that said it picked up the cargo in Damietta, Egypt. An employee of the company’s chartering department said the ship had been bound from Egypt to Cyprus and from there to Lebanon and Turkey. He said the company did not know what was inside the containers or where the cargo originated.

A senior Lebanese army official refused to comment on the Israeli report, saying it happened outside Lebanon’s national waters.

A Hezbollah official, speaking on condition of anonymity because he did not want to speak publicly to the media, said the movement had no comment on Israel’s claim. “We are following the case and we will see if it is worth a comment,” he said.