The United States on Friday accused Iran of close involvement in attacks on commercial ships by Yemen's Houthi rebels, stepping up the tone as Washington considers tougher measures including possible force.

The White House publicly released US intelligence as the Iranian-linked Yemeni insurgents persist with ship strikes they say are in solidarity with Palestinians in the Gaza Strip, where Israel is battling Hamas terrorists.

The White House said that Tehran's clerical state has provided drones and missiles to the Houthis as well as tactical intelligence.

"We know that Iran was deeply involved in planning the operations against commercial vessels in the Red Sea," National Security Council spokesperson Adrienne Watson said.

The White House said that US visual analysis found nearly identical features between Iran's KAS-04 drones and the unmanned vehicles fired by the Houthis, as well as consistent features between Iranian and Houthi missiles.

The Houthis are also reliant on Iranian-provided monitoring systems at sea, the White House said.

"Moreover, Iranian-provided tactical intelligence has been critical in enabling Houthi targeting of maritime vessels since the group commenced attacks in November," Watson said.

The Houthis, who control vast parts of the Arabian Peninsula's poorest country including the capital Sanaa, have launched more than 100 drone and missile attacks, targeting 10 merchant vessels, according to the Pentagon.

Rebel leader Abdel-Malek al-Houthi warned Wednesday that if they were attacked, the rebels would strike back against "American battleships, American interests and American navigation."                                            

WITH AFP