Iranian President Hassan Rouhani said on Tuesday that Yemenis would make those attacking their country regret their actions as a Saudi-led coalition pounded the rebel-held capital with heavy air strikes.

“The people of Yemen will make their aggressors regret their actions,” Rouhani said in a televised speech.

His comments came a day after the killing of ex-president Ali Abdullah Saleh by Houthi rebels triggered a renewed Saudi-backed offensive on the Yemeni capital Sanaa.

The commander of Iran's elite Revolutionary Guards, Mohammad Ali Jafari, said Saleh was killed because he had been trying to overthrow the Houthis.

Saleh had recently broken his uneasy three-year-old alliance with the Houthis and said he was open to talks with the Saudis.

“The traitor Saudis are seeking to create insecurity in the region under orders from the United States and working alongside Israel... We witnessed their attempt to launch a coup against (the Houthis), which was strangled at birth,” Jafari said, according to the Fars news agency.

Saudi Arabia, Iran's main regional rival, has been leading a coalition against the Houthis in a war that has cost thousands of lives and become the world's worst humanitarian crisis according to the United Nations.

Tehran denies direct military support for the Houthis, but a recent UN report said a missile fired by the rebels into Saudi Arabia appeared to have been designed and built in Iran.

In his speech, Rouhani also condemned signs that some Muslim countries were improving ties with Israel in order to counter Iran's growing influence.

“Some Islamic countries have shamelessly revealed their closeness to the Zionist regime,” Rouhani said.

“If some of these countries in the previous years were engaged in negotiations, interaction and cooperation in secret with the enemies of Islam in the region, at least they would deny it in public. Such relations were considered ugly, detestable, sinister and indecent.

“I have no doubt that the Muslims of the world will not let this sinister plot bear fruit,” Rouhani added.

Israel's armed forces chief said last month that his country and Saudi Arabia were in “total agreement” that Iran was the greatest threat to the Middle East.

Lieutenant General Gadi Eisenkot added that the Jewish state was “ready to exchange experience with the moderate Arab countries and exchange intelligence information to face Iran.” The Saudis have not publicly responded to the reports, and analysts say there is still little chance of formal diplomatic recognition between the two countries.

234 killed in recent clashes

Clashes in the Yemeni capital have killed at least 234 people and wounded 400 since December 1, the International Committee of the Red Cross (ICRC) said on Tuesday.

“Now we have 400 wounded reported and 234 dead,” Sanaa-based ICRC spokeswoman Soumaya Beltifa told AFP, in reference to fighting between Houthi rebels and forces loyal to Ali Abdullah Saleh — who was himself killed on Monday.

Strongman Saleh had on Saturday bypassed his Houthi allies of three years, telling the Saudi-led military coalition in Yemen he was ready to negotiate if the crippling siege could be lifted.

But the move backfired. Saleh was killed as fighting raged between his forces and the Houthis for control of the capital — a new front in the war.

Yemen 's war has left thousands dead since 2015, led to what the United Nations now labels the world's worst humanitarian crisis, and has deepened tensions between Middle East rivals Saudi Arabia and Iran.