Iran's elite Revolutionary Guards are ready to provide a military escort to cargo ships trying to break Israel's blockade of Gaza, a representative of Supreme Leader Ayatollah Ali Khamenei said on Sunday.

"Iran's Revolutionary Guards naval forces are fully prepared to escort the peace and freedom convoys to Gaza with all their powers and capabilities," Ali Shirazi, Khamenei's representative inside the Revolutionary Guards, was quoted as saying by the semi-official Mehr news agency.

Any intervention by the Iranian military would be considered highly provocative by Israel which accuses Iran of supplying weapons to Hamas, the Islamist movement which rules Gaza.

Iran does not recognise the Israeli state and President Mahmoud Ahmadinejad has often predicted its imminent demise.

Israel and its ally the United States decline to rule out military action against Iran if it looks like acquiring nuclear arms capability, something Israel sees as a threat to its survival.

Tehran says its nuclear programme is for energy generation and medical purposes and calls its nuclear-armed adversaries hypocrites for trying to block its technological progress.

The Iranian state news agency IRNA said on Sunday Iran would try to send humanitarian aid to Gaza in ships under an Iranian flag. It said Iran had decided to ditch previous plans to send its aid in ships flying the flag of another state.

"The Iranian humanitarian assistance will include foodstuffs, medicines and medical equipment," the head of Iran's Red Crescent Society, Abdolraouf Abidzadeh, was quoted as saying. He gave no more details.

Last Monday Israeli troops killed nine activists on board one ship in a convoy trying to deliver aid to Gaza, sparking international outrage, especially in Muslim countries.

Another ship was boarded on Saturday and pro-Palestinian activists have promised more as they challenge the blockade imposed four years ago with the stated aim of stopping arms getting to Hamas.

Shirazi said Iran should encourage more international efforts to break the blockade. "We should expose our enemies to a spontaneous global action and not let them achieve their heinous goals," he said.

Prime Minister Benjamin Netanyahu said Israel would continue to stop ships reaching the shore and creating "an Iranian port in Gaza", a reference to Iran's support for Hamas.

The Revolutionary Guards, with their own navy, air force and command structure separate from the regular armed forces, are seen as fiercely loyal to the supreme leader.

"If the supreme leader issues an order for this then the Revolutionary Guard naval forces will do their best to secure the ships," Shirazi said. "It is Iran's duty to defend the innocent people of Gaza."