Israel announced that the raid had taken place early on Wednesday in the Red Sea. The navy intercepted a cargo ship sailing under the flag of Panama and carrying a crew of 17.

According to the Israeli military’s statement, intelligence forces have been monitoring the vessel for months. Israeli army spokesman Peter Lerner said the vessel was carrying M-302 rockets that had been made in Syria. He said the rockets had traveled from Damascus to Tehran, where they were taken by land to Iraq before being loaded onto the boat. They were bound for Sudan, according to Lerner, where the rockets would have traveled through Egypt to the Gaza Strip.

“We have clear-cut evidence. We know for a fact that the Iranians are behind this shipment,” Lerner told reporters in Tel Aviv.

The rockets have a significantly longer range (100 miles, or 160 kilometers) than those previously used by militants operating in the Gaza Strip. They would have effectively put all of Israel in range of the militants, whereas their range has previously been limited to about 50 miles (80 kilometers).

Israeli Prime Minister Benjamin Netanyahu was in the United States at the time of the raid but added comments directed at Western countries, including the US, who are attempting to broker a deal with Iran to put limits on its nuclear program.

“At a time when it talks with the world powers,” Netanyahu said, “at a time when Iran is smiling and saying all sorts of pleasantries, that same Iran is sending lethal weapons to terror organizations and it is doing it with an elaborate network of covert global operations with the aim of streaming rockets, missiles and other lethal weapons to harm innocent civilians. This is the real Iran and that country must not be able to have a nuclear weapon.”

Iran has denied the allegations through state-run media channels.