TEHERAN: Iran said on Monday that the Israel-linked ship it seized on the weekend had violated international maritime law and was undergoing "necessary investigations".

Iranian authorities had previously offered little information about why the Islamic Revolutionary Guard Corps seized the ship "MSC Aries" near the Strait of Hormuz on Saturday.

"The ship was directed into the territorial waters of Iran because it violated international maritime laws," Foreign Ministry spokesman Nasser Kanani said.

The ship's crew failed to "adequately respond to questions from Iranian authorities", he told a briefing.

"It is certain that this ship belongs to the Zionist regime," Kanani added, referring to Israel.

The ship's seizure took place hours before Iran launched its first-ever direct attack on Israel, launching hundreds of drones and missiles, which the Israeli military said were nearly all intercepted.

The attack was in response to a strike on the Iranian consulate in Damascus on April 1 that killed seven Revolutionary Guards including two generals - and was widely blamed on Israel.

Israel and the United States have denounced the seizure of the ship as an act of "piracy".

Israel has also demanded that the Guards be declared a "terrorist organisation" by the European Union.

Regional tensions have soared since war broke out more than six months ago between Israel and Hamas in Gaza.

Iran has supported Hamas, but repeatedly denied direct involvement in the Palestinian group's October 7 attack on Israel that started the war.

 - AFP